I'm not so sure on that last point... You guys don't set your hops to 0 between games do you? The game season is longer than the off season, so if you store your guns with hopups preset, you're holding their form out of shape longer than you are than the off season.
I'm skeptical about that one. All the rest is practical maintenance.
Clean your barrels too if you get the chance... all sorts of garbage ends up in it over the season.