Few questions for Ashes fans from someone with 7500+ hours in sins

It should be noted as well as the 7500 hours in sins ive probably racked up the same in Supreme commander (but not the 2nd one ha)

Big RTS fan, i got the early access for Ashes but i was hooked on another game at the time so it just sat in my account, ive had a couple of attempts at playing it over the last year but could not really get into it in skirmish or the campaign,

I decided to try again after i read two things i really liked the sound of

1.  This table - https://steamcommunity.com/app/507490/discussions/0/217691032428932963/

2. the opening line in this article http://www.pcgamer.com/ashes-of-the-singularity-escalation-dlc-adds-two-new-campaigns-and-a-strategic-zoom-option/ 

So ive decided to play the original just to blast through the campaign and then jump on the newer version but im on the 6th mission and have a few questions.

I love RTS but one or two things i just dont get and wanted to ask you guys cause i figure some the people on the official forums will know most of the Dev Q&A's by off by heart, and i didn't want to post somewhere like reddit because im not complaining about the game and i dont want this post to have too much attention except from the core fans.

ok so here goes      i am enjoying this game but i have a few questions on why some things are the way they are.

The resources being connected by "lines" and indescribable buildings. Is this explained why or is it just the game design choices? for me indestructible buildings ruin my immersion as they dont make sense unless its explained with some ingame lore (they are constructed by X material by an extinct species and the tech cant be replicated ect)  and the lines i get they change colour to indicate regions of control but since you can build anywhere i dont quote get why it was designed this way?  the lines are a type of eye sore - does the lore explain what they are there and is there a way to turn them off or a mod that hides them - and same for the magic indestructible resource buildings - any mods that let me blow them up? 

Building limits - Unit caps make a bit of sense for hardware / engine reasons but why oh why has the game limited defensive structures? again totally immersion ruining - something i get for multiplayer player competitive but its just shoehorned in for balance reasons.   Is the only way to defend a base to use units?  one of my fav things to do in all RTS games is to build the "perfect base" a true fortress.   Can anyone recommend any mods that remove this limitation and does the AI adapt and play differently with it?  

Structure placement - when you go to place the structure acts like it is aligned to grids (small movements - like micro adjustments are not possible) Is there an option to see terrain placement options for base building for forward planning. Red areas where they can not go ect.  I get you obviously can not place on a cliff but i can place on hills and slopes - but then sometimes there is a section of the slope i cant place on and the building will show up red.  Is there a way to toggle on or off a placement window/highlight   where it shows red areas of the map where a structure can not be placed so i can plan the exact position of future buildings 

Unit colours - as above im on the campaign now i think the 6th or 7th mission and i can see some neutral units on my map that i have explored

1. They are blue (same colour as me) Can i change the colour of neutrals

2. I am looking at them but they dont show up on my mini map? and i even have a sensor array built and they are right beside my base.   My aly on the mission is sharing satalite data so i can see orange guys on the far side of the map but the blue neutral guys dont show up

this next part is why i alt-tabbed to post.  

My map started with my main structure and a few other pre built structures including 2x Falcon Anti air buildings.  Only one way into my base along a corridor to the south. I had a ridge protecting me to my north and an allied base over the ridge to my right so after i defeated the neutral units and built resource structures all around my base i built some defensive structures at the only way into my base and then i destroyed the 2x falcon air so i could relocate all my anti air to the base of the cliff to the north of my base because i need to defend my northern resource structures and also its the only way into my base from air and having any anti air there will render the 2x falcons obsolete.  

But i cant rebuild them? i can build smarty systems that target both land and air but i cant rebuild the buildings i already had (and logically i should know how to build them) They are not even greyed out indicating that i need more research/quantum upgrades and i dont understand why i cant replicate them?