There are a few trolls who need to be brought under control, but other than that, I see no need for extra moderation.
An ignore button would go a long way toward fixing that, IMO.
An up/down voting system with the result of enough downvotes in relation to the upvotes being a TROLL marking, similar to the SCAMMER one (maybe little troll icons instead of coins)?
I'm sure some of them would wear it proudly.