I have been a long time fantasy and 4x fan. Bought the original Elemental, shelved it pretty quickly, and recently discovered FE and my beta access.

First off: Great job so far. FE is loads better than EWOM, and the recent 5C really started to nail it down to feeling like a polished game rather than a quest engine. The troop/champion balance is much better, cities feel useful, and the tactical combat engine feels smoother and more polished. Now for my comments...

Bugs I have noticed: (Some of these are from previous betas, but I didn't explicitly see that they were fixed)

Surrendered sovereigns not appearing: I didn't even know I had them until they got attacked. After the battle, I couldn't  see or select them, although the area around them was explored and when I moved over them they joined my army.

Disappearing tactical bar for units in some cases.

Bugged unit hp bars in tactical combat.

Disappearing towns/outposts

Floating waterfalls

Blacksmiths don't give out bonuses to all armor categories (or their tooltip needs to be fixed)

Some more general concerns:

City razing destroys fertile land. This feels very harsh, especially with the odd way in which monster AI is implemented right now. 

Cannot see how many armies are in a tile: is there any reason not to limit the total amount of armies to 1 per tile?

Don't move into defeated armies tile after offensive battle

Gaining multiple equipment from a quest or battle leads to a spam of similar dialogues: if I hit trade there is no need to inform me of each one.

Can shop in enemy lands. This just doesn't feel right. 

AI only seems to meet with me if there is an adjacent unit, but not when wandering around in their territory. 

I would like a few more diplo options: resource per turn trades, more ways to demand tribute, etc

Monster AI still feels off: they often don't attack (especially not the AI) and will wander around aimlessly in my lands, making me complacent and likely to expand. Then all of a sudden they become aggressive and sack a few cities, which are not rebuildable.

Can't see unit stats in tactical combat: This is the most important one for me. I can't see their equipment, weapon, or what kind of damage they are most vulnerable to.

Can't fortify non-fort cities. Being able to build some level of palisade / increased defender groups in all cities would be nice. Alternatively, defenders could make use of some research (use no armor, weapons 1 tech level below your current, and use your current max unit size). 

General critique of game elements

Basic Units
Basic units feel a bit boring. They aren't supposed to be as interesting as champions, and I certainly don't need to feel attached to my
mass produced fodder. However, it would be nice if they had a few interesting features, especially for highly levelled veterans. Right now,
levelling gives a bit of hp, accuracy, and spell resist, which is actually quite useful (especially the first few bits of hp), but feels a bit boring and becomes
much less useful later (going from 7 to 9 hp is a bigger deal than from 13 to 15).

Suggestion: Mini 'path' based on elemental types which give different bonuses, or a larger random bonus every 5? levels (or both)
eg Rage (requires access to fire shard) + 5% atk per level, +crit chance; Flow (requires access to air shard) + dodge, initiative
Charge (can randomly gain at level 5), 50% bonus damage but cannot move next turn, several turn cd

Upgrading units: Upgrading a units equipment seems prohibitively expensive, especially since my cities could produce the production for that equipment in a few turns.
Upgrading to a different unit size doesn't appear to be possible, which really weakens the power of a well leveled unit over time.
I would like to see some way to either pay to add units to a group, or sacrifice a promoted group to pass some of their xp to a greenhorn unit.

Champion Balance/Utility
One of the selling points was that we could use champions almost exclusively for 4x, or the other way around.
The new patch brings a great balance to champions vs civilization, but only at one level.
That is I should be able to focus on my sovereign and champion somehow, by using my production / research to more directly benefit them.
Alternatively, there should be more ways for champions and sovereigns to impact cities and armies.

Suggestions:
For civilization focus: expand path of the governor with more unique and interesting skills, such as +production, +% gold/research/mana, bonuses to trained troops, etc. Also need some way to gain xp (since they won't be doing much combat)
Allow a path such as "Path of the Commander" with a focus on buffing an entire army rather than just the champion.
Ways for quests to be spawned by or for cities: eg can go on a quest which could discovere a resource, or give a lesser version of an elemental lord trophy
For a champion focus: Perhaps a set of researchable champion only items (or too expensive for groups) at higher tech levels, perhaps requiring construction of a special shop.
Mid game champions start getting clobbered by size 5+ units with decent equipment. Allow construction of special buildings which can improve champion stats, such as a arena where a champion can gain a hp at the cost of several turns of production (with diminishing returns, increasing cost, or a cap)

Items
Horses and Wargs seem too good, especially since they give both moves and initiative. Linking strategic and tactical moves cuts down on stats, but it really makes mounted units quite powerful in combat.
At the very least, horses should have a production cost associated with using them (time spent training the horses?).
Overall, champion / sovereign special items feel correct: low level quests give appropriate items, while some of the later game items are awesome.

While exploring the world, it seems far more likely that the Sovereign is going to find a few medium quality spears than 1 glowy super sword. I wouldn't mind some specific army group type weapons that can be given to units as a quest reward.
Alternatively, perhaps a sovereign should be able to bring equipment back to be copied, so if you find a few sets of chainmail you can teach your smiths to make it for your troops (perhaps at higher cost) before the research is done.

Research
Specifically, upper level research. The upper levels of the tech tree feel boring and generic. If I have a tech advantage, I would like it to have some
sort of wow factor, rather than a generic +10% damage. Adding a unique new equipment, trait, spell, or special unit would make these techs seem far more interesting (even if the actual ingame impact is far less than the 10% bonus to accuracy or whatever)

Cities
Early game, cities are fun, and the choices with specialization keep them interesting up to mid game. However, the latter half of the game, cities are severaly lacking. I recall hearing a dev say that they never wanted cities to be able to run out of things to build.
This actually seems to happen to me quite a bit. This is mostly caused by the tech tree: as you go higher up, techs provide less unlocks, and the unlocks tend to only be buildable by one class of city.
This hits especially hard in non-troop producers. I want my troops to get the benefit from enchantments/buildings in my forts, so I don't want to build them in other cities. However, if I have already finished the food line of buildings (in towns) or research lines (in conclaves) there isn't much else to do.

Resources
Resources tend to be a little bland, and make choosing where to settle fairly arbitrary (choose only for tile yields).
Adding more 'special' resources that appear in conquered wildlands would help promote clearing/settling them, and make them more thematic.
Having more 'lategame' resources that require high tech to unlock would add a dynamic of risk v reward, or is it worth the investment to control this territory now fo rthe boost later.
Examples of special/lategame resources: Gems (more powerful gold), ancient armory (allows access to special perks or equipment or an army boost), nightmares (elite mounts)

Magic
Some spells feel ridiculously powerful, such as haste, slow, blizzard, growth, and many more.
This is exacerbated by fairly easy to get and stack perks which give significant boosts to damage or mana reduction.
A few of the major offenders:
haste and slow: Absolutely devastating against many monsters. Perhaps they should chance the initiative to move (from 100 to 85-115) rather than change initiative.
Spells which give damage per unit: with the low hp most units have when being trained (single digit is common), these spells can wipe out entire armies (especially blizzard)

The real problem isnt so much the effect of these spells, as their effect on the ai.
Many tactical spells make challenging quests become trivial: a slowed and shrink dragon is incredibly weak.
High level monsters should be able to remove debuffs (either passively over time or every few turns as a skill), or be significantly more magic resistant

Spells like blizzard have a fairly easy counter with dispell...but the many quest fights dont have spellcasters, and most AI stacks don't as well.
Adding something from above to monsters would help with quests, but what about the AI?
Suggestion: Adding a spellcasting unit (wizard or adept)
Fairly expensive and fragile, but can cast a few basic spells: perhaps a half chance dispell, a few weak debuffs/buffs, one weak direct damage
Their high cost, fragility, and weak spells from same mana cost would limit their spammability, while helping to counter enemy spellcasters

World
The feel of elemental is excellent, with monsters and quests roaming the lands and high level areas adding interest.
My only suggestion here is a few more areas, especially lesser ones (like the scrapyard), perhaps with unique resources or features to add some differentiation.

Faction Differentiation
I don't know how much faction differentiation is inteded, but right now I don't feel like there is much at all.
Usually there are just a few different / restricted equipement changes, and perhaps 1 unique building per faction (Pretty much a UU and a UB).

Suggestions : The cool faction specific units (like cenotaph, etc). Could have either a reduced cost or a unique skill compared to building them normally
Additional changes in faction building lines (ex a empire food line produces less food but improves training time or unit hp)
More unique unit bases: The iron golem and the juggernaut are pretty much the only factions that feel really unique.

Tactical Depth
Possibly the area that feels most lacking. Currently, the main strategy is to run up to enemy units and hit them. Champion may cast spells, but for basic units (unless you are kiting), the only real strategy is to just walk up and bash eachother.
That is, I fell little need in tactical battles to specifically focus enemy mages or ranged units, to match the units I am fighting with enemies who have less armor against that damage type, etc.
Essentially, the combat feels completely determined ahead of time by the number and quality of troops, which raises the question of why even have the battles?

Suggestions: Terrain effects: Speed, slow, reduce / increase taken damage, dodge, accuracy, healing, etc
Additional specialization in weapons / armors: I can't really focus my troops to have superior crushing defense, but I wouldn't want to anyways since my opponent can easily swap to another damage type. Perhaps some level of additional research in weapons / armors (magic types as well) to add a more strategic countering?
More skills: things like fortify that have an effect on the battlefield (
eg shield wall - reduce damage to adjacent units
bash - low damage skill that reduces enemy stats
support - counterattack anyone who attacks an adjacent ally
healer staves which do no damage but can heal
Ranged differentiation: Adding specialization would help make fire/lightning/cold more unique, as is its equally easy to get and counter any of them.
Add a difference between bows and staffs: Bows could be higher damage, but have an accuracy dropoff over range (this would also help with kiting). Staves could do less damage, but no range penatly and have a change to shock/freeze/burn

Conclusion

Many of the above suggestion are probably impractical to implement or would quickly make the game no longer fun. I mean them more as guidelines as ways to deal with some of the main game play issues I see rather than as actual things to be implemented. The main gameplay areas that I think could be improved are: 

Civilization vs Champions: They are fairly balanced now, but interaction is limited, and I certainly don't feel that I can focus one way or the other. I can't go on quests to improve cities, use my champions meaningfully to improve my armies or cities, or use my cities to empower my late game champion units.

Standard Units: They become little more than 'move to enemy and attack' spell fodder. Fodder has its role, but allowing standard units become interesting as they gain xp would improve them.

Tactical battles: For being such a major part of the game, there is very little tactical strategy here. Not every battle needs to be complex, but large battles again epic quests or enemy sovereign led armies feel anticlimactic since the general strategy is either to bash our units together, or abuse kiting and ai weaknesses to magic. 

Replay Value: In general, more content is more replay value (although it can be harder to balance). More quests, more land areas, increased faction differentiation, more unique worlds through use of rarer resources, etc would all increase this.