As long as people keep it in RM, it's fine. I personally don't feel it's necessary to have too many rules in RM, mainly because the purpose of that forum was to give users a place to post freely without fear of getting into trouble. However, the rule does apply in The Lounge, so users shouldn't hesitate to report to the staff if they feel bullied or harassed in there. New users are advised not to introduce themselves in RM, and I will write that under the forum description.
Now, I think we can safely say that we're quite fed up with the "alt hunting" thing. Accusations do more harm than good for the forums, as others have said. When new users log in for the first time but they look suspicious, don't immediately accuse of them being alts. Welcome them instead. Let the moderators do the work. If the account hasn't been banned yet (still active), it's a message from the staff that said account is not an alt.