Well, if a subject starts to get out of hand(as in people start to flame or starting to personally attack someone) the thread in which the argument is escalating can always get closed by a mod. As for actually dividing the community. I can see that it can bring tension to a small number of folks, but I don't think it'll tear the community apart. I've seen debate sections on forums work, mainly because of strict rules of what specifically what and what not to post(whether it be subjects or what to say).
I think so long as the threads are being monitored, I say let's give it a go(even though it's already in place). I'm very curious as to what'll be posted, though I may not post in it much. The Religion one is a bit worrying, though, since that tends to be a very touchy subject and can easily start flame wars and it's usually ban to talk about on most forums(even in debate/mature sections). But, whatever you want to do is fine by me.