Sorry to hijack the thread, but as for the banning:
instead of banning people, rig the board to dickroll them based on the account info and also automatically temporarily set their IP to get dickrolled even when they clear cookies/don't log back in. So they would get dickrolled on every request to the board (or maybe only when they hit reply).
Once you notice the same person has created a new account, add that account to the dickroll list without announcing it.
I bet it would be much more disappointing for them to be getting dickrolled out of the blue just as they were about to make their next reply.
But make sure you don't redirect it to one of the few "well-established" domains, since those can be blocked easily. Instead, host the dicks right on the board.
That might deter them from coming back under different usernames.
I don't know the internals of this board's software, but it shouldn't be hard to implement such system.