I heartily endorse Kapeman's wish list and would also like to see melee fighters placed first on the combat screen ahead of ranged attackers. That would also greatly improve the game.

i would really like some more of the spells to be put (back?) in. as essential as all the other stuff is, i'm starting to get bored seeing all the same stuff over and over again. what happened to the fire giants and elementals i could summon? i can't seem to find them anymore. in my last game i actually managed to research every spell in the game i wanted by the midgame, using only the research from my arcane temple (ie, no scholar buildings). some more quests would help too.

4 man minimum unit size cannot come quick enough though.

@Dsraider, i would really love to see the maritime side of the game get some love, but there's so much cool stuff that can be done there (as you mentioned) that i think it's better left to an expansion, and done altogether (and really well), rather than  in drips and drabs in patches. too many unbalanced, unintegrated mechanics in the game already.

on a related note, how difficult would it be to add a "Craft" button to the merchant screen, that allows you to buy things for your sovereigns using resources instead of gold? it would then be very simple to add magic item crafting recipes to the store - these would essentially be items you could only buy with resources (including midnight stones or whatever).

just seems like an elegant way to do it.

Agree with OPs list and most of the above, including ability to craft magic items and desire for more spells.

My own requests / complaints are:

1:  In most of my campaigns on max-sized maps, I end up running out of spells to research, especially if I don't have all 4 starting elemental books.  Either add more level 6++ spells, or some refined spellcasting that increases the effect of some spells, similar to what intelligence does.  Or both.

1a:  Maybe also let those who don't start with th 4 elemental magic books research them later.

2:  Re shop interface improvements:  I'd like the ability to cycle thru units in a stack without leaving the shop.  And of course ability to filter the items it offers to sell me.  Only high-level items, only armor, only rings, etc. 

2a:  I wouldn't mind some items in the shop to enhance archery and magic resistance.

3:  How about cutting down on the near-duplicate items?  Healing potions & salted pork both give the same benefit for the same price -- why not have one give more benefit for a higher price?  Or maybe make one give a random boost or a percent of the user's hit points instead of a fixed benefit.

4:  Why have 2 multiple mounts that differ only in color?  How about more expensive mounts that are faster, or give extra attack because they kick & bite?

5:  Nuke Solon the Gladiator.  His special ability applies only to sovies.  He doesn't get it.

6:  Give us a way to speed up movement / animations in tactical combat.

7:  In tactical combat, make sure the resulting damage is reflected on the target's unit tab immediately.  It used to be like that, but now it usually doesn't show until the next thing happens.

8:  Fix autoresolve to use special abilities and understand that it takes time for melee troops to get in range of archers. Currently it seriously undervalues special abiltities like "crushing blow", archery (especially mobile mounted archers) and any non-retaliate attack like Xander's (from the book extra content) feint ability.  This may be a hard one to program, but it is my most important request.  I've seen threads complaining about boring tactical combat, and I think the best way to make tactical combat less boring is to make autoresolve work well enough so we won't need to fight so many battles ourselves.

Strategic AI + Tactical AI.

Nothing else matters until the AI can actually attack and threaten the player.

 Not only that, but I hate the store for being so fiddly. I'll have a group of champs in armor and then research a better armor, but rather than visit the store and upgrade them all then have to sell the obsolete pieces, I'll think, maybe I'll just wait until the next armor advancement so I don't have to go through that whole process again. Maybe I'm just lazy?

What I've tried to do to make the game harder is only to use family members for offense. Once I get Legendary plate is it (The armor from the magic line) I'm pretty much invincible. I find it odd that it costs Elementium for regular troops but a big bag of cash works for royalty (might want to add resource costs for heroes too).

And recipes/crafting materials could be goodie hut loot.