@Uber -
In general, I agree with you. We don't want to become the "thought police" around here. And I would agree that things that some people consider "inappropriate" can in fact be appropriate for Diplomacy. If I want to berate you and call you an asshole, or a dumbass for stabbing me, or other insults, it can all be part of the game in trying to get people to do what you want.
That said, there HAS to be a line or it becomes a free-for-all and could breed a very toxic atmosphere. The lines quoted above are a good example of that, and I'll repost them below:
":listen here you absolute Autismo go back to you're igloo you freezie fuck"
"come back when you learn proper english you autistic fuck"
"FUCKING NIGGERS"
"shut up niggeral"
"ha gay nigger"
Look, are we really going to say these types of comments are OK? Putting aside the fact that this type of interaction (in a game that was NOT private, in that it had many people from outside their friend group) can make a significant number of people uncomfortable, we also have to consider who is on this site. I don't know for certain, but I'd wager a good amount that we have at least one black person, one gay person, and very possibly an autistic person on this site. These type of phrases breed a hostile atmosphere to people, and serve no purpose to write. We also need to remember there's probably some fairly young people on here, and letting them think this is "normal" communication skews their viewpoint for the future, and not in a good way.
Look, I'm all for good fun, and even good insults. But this reminds me of high school and when people thought they were "cool", when really, they were just obnoxious and insulting. We're better than that.