I think the hardest question is how to mark a node as being a troll post. A rather simplistic approach would be to set an XP threshold, for example -5, and consider everything below that trolling. Or we could reuse the consideration mechanism. Or have a different method altogether.

I personally believe that troll tagging would be nice. But basing it on node reputation would not be appropriate. In fact nodes by some reputable monks sometimes happen to be heavily downvoted, due to controversial opinions; but they're not trolls, by any means. (Incidentally, IMHO Win is not a real troll either, rather an annoying crackpot exhibiting trollish behaviour every now and then.) The consideration mechanism would be ok for this task.