Yeah, I post in a lot of other sections here, but never in NU/W.
You don't have to worry about receiving negative rep points. They don't really mean anything (and you can disable receiving rep if you want). Rep's just a fun thing here at PC. But, if you think that someone is messing around with your rep too much, let a staff member know so we can take care of it.
Just as long as you follow the rules of the forum, you don't have to worry about being banned. ^_^