There's basically 3 options when it comes to moderation.
1) Low touch, depending on the posters to keep each other in check
2) High touch, which relies on a full time team of moderators reading every post as soon as it appears and moderating as they see fit
3) Pre-moderated, where every post is put into a queue until they are approved and published
Number 1) is really the only workable option for a site like this.
As for the moon howlers (btw, what happened to not liking abuse?) they have been killing groups, sites and services since the September that Never Ended. If there was a simple way to eliminate them, billion dollar companies would have found it by now.