I'll try to answer the questions per section based on the experience I've received so far in the testing...
AI
The system is still be developed and how it will act on live servers still hasn't been fully addressed.
But as for how they act, basically take having your friend on teamspeak with you and you tell them "Hey go repair the Obelisk" well he should go repair if he's close enough and isn't already actively engaged in defending. Now the AI act almost exactly like this, except they are a bit more responsive and more likely to pull off an attacking target to complete the task that they were given.
Rocket Launcher
You can't spam it like you can in most games and the damage isn't as wide spread as you think, takes some work to hit your target even at medium ranges.
Air-Strikes and the like
I haven't seen anything other than ION/NUKES in and i haven't heard anything about air strikes
Overall Tactics
The mammoth CANNOT fire main cannons and missiles at the same time. The missile rack for the MRLS turns with the camera, no locking position but does allow for tracking after a certain amount of time on flying vehicles (quite annoying IMO >.>) The laser rifle has gotten an upgrade and actually sounds pretty awesome when its fired, and you can hear it at quite the distance. They are keeping the balance of the vehicles to the original ren as much as possible, the arty does have an arc, but not a major one, and the missiles on the stank do fire right after each other but the time delay is minimal to prevent collision of the rockets ( i'd assume). As for the blue Tiberium, i can't speak much about this since there isn't much information on this just yet and of course it too is still being developed.
Final remarks
Keep in mind the game is still in heavy development, watch out for Fobby's updates for more sneak peeks!
I hope i relieved some of your concerns!