The answer to the crater issue could be addressed with an appropriate persistence value. Have them repair in say, 10 minutes, for example. That would be too quick to completely dominate a field and not long enough for a return flight with more ordnance.
I also played Fighter Ace and found the cratering aspect manageable and, most improtantly, it proved a viable and worthwhile interdiction tactic.

Adding the cratering element also adds something to the realism of the game, in my opinion. Fields won't go without cap as they do now, hence, you will have a greater reason and incentive to protect them.
David
More about interdiction tactics here.