What house rules do you use?

I have to house rule a few things, including the special ability about attacking at Range 0. If you're at Range 0 and attacking a fighter, that fighter can't fire back (unless it has a Range 0 special ability. But a bomber (in the game, only the Bf110) should be able to attack at range zero if the fighter approached from a direction that would expose it to fire.
So, if the fighter comes in from 4, 6 or 8 o'clock, it'll take fire from the rear gunner.
Because I have added so many non-AAAF aircraft (He-111s, B-17s, etc) to the game, there are a lot of aircraft-specific rules.