1. i don't have any examples since i'm not currently in any games, BUT
2. the basic rules formats i usually see come in three parts (and i find it easier to divide them this way when writing them): 1) player conduct and expectations, 2) character creation and storyline rules, and 3) world-specific rules, or what is and isn't possible per the game's canon. generally, the fewer the better--a lot of stuff one would be tempted to put in the rules can just as easily go in an faq section. that said, i like it when games have rules that address certain storylines, like "certain topics [rape, self-injury, ed, etc] are very triggering to some players and require mod approval and an lj-cut with a warning when they do get posted about", and have pb requirements--i.e., games that require people use ethnically/racially/age appropriate pbs.
3. when i was 16 games that had an 18+ rule made me so mad :P no but seriously, umm. ridiculous activity requirements, "passwords" you have to put in the app to get accepted, post word length minimums. journal name requirements i hate, although i accept the wisdom behind banning usernames with excessive underscores or random numbers or x's or whatever. i agree about the tone of the page being appropriate--you want to be firm without sounding like a dick. injecting a little humour never hurt.