I think you nailed it with the categories - it certainly takes any of the issues I put forward out of the mix. That might be the ticket to keep things moving nicely, especially as the community grows. Sadly the devil's advocate hat is more of a touque (as we say here in Canada) or beanie for seemingly the rest of the world and is sorely lacking in the horns department.
I think this would work very well if moderated and categorized. I would certainly put my vote in to have you administer it as well.
I think this framework should work well and we can always tweak it slightly as we go.