I'm a firm believer in fewer moderators. More moderators mean more people in charge with different ideas with what can and won't be tolerated. In my opinion, the moderators we have are doing a fine job and I really don't see any problems. There are always going to be a few idiots on the forum, just warn them once and if they don't behave ban them.
The
www.fiero.nl forum has almost 9,000 members and has ONE moderator and it is the best run forum that I have ever been a part of. They have a rating system to regulate the trouble makers. I didn't like it at first but it works flawlessly. They also have a "trash can" where shitty threads get moved once they get out of hand but you can still view them.