Moderation should be approached like web security - any feature has potential exploits. Expect the flag patrols and bury brigades because if you allow folks to downrate or flag, someone will abuse it.

You know, the only site that had moderation pretty much figured out (meaning: signal to noise ratio is much better than rest of internet) for over a decade was Slashdot.

Making the system both resilient to attack as well as usable for it's intended function is not straightforward or easy. Hey, I hear that Malda is looking for work... I'd hire someone like him or a Wikipedia veteran.