1. The rules cover conduct expected in-game, and should be enforced with respect to rudeness, non-settings compliant names (guild and character), etc.
If you mean that very obvious interuptions of roleplay and the settings should be responded to by game masters, I can agree with this.
2. Forcing people to "actively" RP is a bad idea.
Yes. We should stop people from hurting the roleplay environment, but we can't force people to roleplay. We can however do things to limit activities that are out of character, even when they don't directly hurt the roleplay environment.
3. Expecting PLAYERS to be courteous and in-character should be the norm. Players must be courteous, even if their character is rude.
There's a good thread on this topic called IC baddies versus OOC goodies or something. I think we need room for evil characters, evil actions, and rudeness. I think that it's extremely tricky though. A character who spits is one thing. A character who spits on others is something else, even when it's supposed to be IC. Often, people will roleplay things like that, but only to characters controlled by players they don't like. And often it's completely unnecessary anyway. So maybe there should be strict limitations on IC rudeness, especially since IC rudeness is often a disguise for OOC rudeness. There are many ways to roleplay dark, evil, or rude characters, and only some of them stand the chance of hurting OOC feelings unintentionally.
4. How on earth do you enforce "better" RP beyond the obvious netspeak or rudeness issues addressed in 1 above?
Addressing bad behaviours. Providing models of good behaviour.
Did I miss anything?
Yes, but there's so much to write on the topic that it probably isn't wise to address everything in a single post.