RE: The religious thread. I didn't see it, but we seem to have attracted someone with the last name of grassi or grossi who posts some sort of religious stuff, with the caveat that the post will probably be deleted. I've reported at least 4 or 5 of them. Chance are it was him/her again.
The idea of minimum posts before starting new thread is a good one. I've also seen minimum posts required before being able to post a link. That one may get rid of the people who register only to advertise their business.