How about creating a safe, sane, but not necessarily tame discussion forum for those with many posts (1500 or so)? The gated forum would allow seasoned posters to freely and intensely discuss controversial issues, without allowing trolls and flamers to ruin discussions (if you could get through thousands of posts without being perma-banned, then you're not a troll).
I am against creating a two tier system. Every member should have equal access to every topics as long as they follow the rules. What if a new member has something insightful to add to a controversial topic. Private message is the venue for untamed discussion.