Community is another. While the mechanics are well discussed I found http://www.makeuseof.com/tag/5-great-sites-create-forum/ interesting as they listed over a dozen robot moderators there.

So what's stopping you? The biggest hurdle I find today is that folk don't do things. That is, they will spend all their time investigating rather than doing. I'm sure you've read the pottery example at http://www.codinghorror.com/blog/2008/08/quantity-always-trumps-quality.html

Your last question was how to handle your forum site. I think those auto mods are a great way to tame the eventual spam flood.
Bob