AI nodes would be nice.

There is already nodes for AI. Ground nodes, for soldiers and hunters , strider nodes, and nodes for city scanners

I'm planning to add nodes for choppers and gunships

on four you could do an watchtower area near the bunker

with spotlights on them

That seems like a nice idea. But currently I'm working on skybox rebuild and nodes for hunter-choppers

Well skybox and watchtower finished but chopper nodes are not working. The chopper is like "♥♥♥♥ it. I'll hover in one place forever"

Already finished the watchtower. It don't have a spotlights but it has two player-npc useable turrets.
They can be used by player, combine soldiers , metropolices, refugees and rebels like in hl2

can you make citizens walking around

I can make separate version with citizens because they can lag on weaker computers

i just want to you add cool new ai or car into the map to play with

more underground stuff, me and my friends messed around on this map and it was a blast making a fort out of the underground base that was availible

I can expand the bases. That would not be hard like making entrance to them. I can also add some fake DMM (destructible) stuff like walls or something. There will be a watchtower near bases in next version. I'm currently not at home so I can't do this now. I will try to update this one instead of uploading v4.

Perhaps a few more buildings (Doesn't have to be enterable) It would be even better if you placed them in a small corner of the map to make it seem like this is a little oppressed combine village consisting of five or more small little houses.
That, and expanding the bunker? With an armory area and a lab area similar to Construct Conspiracy?

I don't know what is Construct Conspiracy but yes I'm going to expand bunker with an armory and I can make small village.