In my humble opinion, here is my solution...
Bring back the AUP. Perhaps refine it if need be. Enforce the rules much stricter in the RW forum and have special rules for it. Give everyone a fresh start for the RW forum. Violators after three warnings are banned from the RW forum, not the board, for three months. If it is warranted that the same person needs to be banned again later when he returns, then it is for six months. The third offense would be banned for a year from the RW forum.
By doing this, the offenders that are ruining the RW forum are cut out from the forum, not the board, and are still allowed to post around the board thus it would hurt the board as a whole to ban a member from the forum.
The RW forum is the beef of the board. Most other forums just contain idle talk. If it is ever going to be gone for good it will hurt the board.