I don't know if this has been wished for before but:
I think that when you capture a base, the ack shouldn't automatically go up like it does now on the captured base. Force the group that captured the base to have to defend what they just captured, up to strength. This will eliminate the 'whack a mole' gameplay problem, which is when a large squadron captures a base and then vanishes to the other side of the map leaving the resistance with nobody to fight. If the group that just captured a base has an incentive to stay and defend, then they will, simple as that. They will not want the base to get snuck back.
With this, I also propose that bomb splash damage be increased to help heavy bomber effectiveness on a town, and also, increase the down time of a town. With Lusche's capture stats, it clearly shows there is imbalance in the game now with captures being reduced by half since the town updates.
I feel that these simple changes will help rebalance the game and also encourage better fights.