Rarek - thanks for thinking of medics! When I modded domination for myself, you had to kill X number of enemies to get enough credit to respawn at the MHQ and it would deduct from your score when you do. This also prevented BF3 style play where you could just teleport, get killed and re-teleport endlessly. Perhaps putting in this type of requirement could be considered. Domination used this to call in airstrikes at a cost of 5 or 10 points each if I remember.
You could also allow medics to create MASH tents that would allow a limited number of heals to anyone who enters. A strategically placed MASH tent could allow for more emergent gameplay without killing teamplay.
The reliance on choppers adds so much to the immersion factor in I&A - I hope adding MHQ will not diminish this, but there is plenty of time to figure it out. Good work!