Sounds like a good idea to me!
I doubt it- there’s no way to limit/prevent a user from posting here which would be a greater form of ostracism than arguing with the person in question: arguing or questioning a user elicits a response from that user; limiting access would … limit access and be a form of ostracism.
Perhaps if there was a way for users to subtract points from posts, rather than add points to such posts that are negative, and use this method to limit, by some measure, how many times a poster may post on a daily/weekly basis; or allow a poster to limit the audience that can see a post to his/her friends; or prevent a user from seeing them or posting on them.
I’d imagine these adjustments (unlikely that the forum will be modified from what has been posted regarding perceived faults) would produce different results. Then again, maybe not.