I think the biggest problem with the air support is how it is implemented, esp. against tanks.
IIRC at the moment the air support has a list of priority targets, with tanks being lowest priority, meaning that they hardly ever get targeted. If we could choose what type of enemy to target, with a greater variety of weaponry, this would be much more useful.
Also, I'd like to make the fighter cover universal and non-player-controlled, as currently when the enemy's planes attack, and you call for fighter support, it always arrives too late.