Backtagging: Sure
Threadjacking: Sure
Fourthwalling: No thanks
Offensive subjects: His mother's death? If you're gonna be a dick about it.

Hugging this character: Yes
Kissing this character: Yes
Flirting with this character: Yes
Fighting with this character: Yes
Injuring this character: Warn first OOCly, but in theory yes.
Killing this character: Warn first OOCly, but in theory yes.
Using telepathy/mind reading abilities on this character: Warn first OOCly, but in theory yes.