I learned a couple things:
1) Don't wait until there's only 20 hours left before the P38L mission expires to finish about half of the missions.
2)The game doesn't properly reward cappers. When I was knocking out the "Destroy 100 air defense aircraft" mission, my win/loss rate when up by about 10 percentage points.
The problem? I was hopping between red sectors, clearing out air defense aircraft, capping them and then for achieving the primary goal of the game I would get maybe 5 or 6k points. No wonder so many people just chase kills instead of actually trying to win the match.