(for instance, can I post a novel I am trying to write)
I will let mk speak for himself.
"R" or "X" rated material is to labelled,
I'm not sure we have much of that to be honest.
and if tribes exist on this site (like in our country).
Where there are people, there is almost certainly going to be differences of opinion on controversial issues. Hubski has people, so there are differences of opinion, especially on controversial issues.
Make yourself comfy, poke around in the tags page and badges page, as my personal suggestion.