Mine are pretty young, so the only one I object with is knowing your role. While I agree that the coach is the one that provides instruction and rules of the game, I have seen many behavior situations where a parent should have stepped in (these kids are under 7yrs old). The coach should not the babysitter or disciplinarian.
http://www.thepostgame.com/blog/more-family-fun/201202/what-makes-nightmare-sports-parent