Glad to see you managed to get your site fixed after a Panda hit!
I too own a modest forum and it also has been hit.
I have see your video interview and read your posts here and there and have been implementing similar changes to avoid Google finding/indexing thin content.
One of the things you did that interested me was noindexing 0 reply threads... as far as i can tell you run a heavily customized version of vbulletin but for the life of me i cannot work out how to add the tag to just these pages, if conditionals dont seem to play ball.
Would you be so kind as to reveal how you did it, you could be saving another business from ruin after 6 years hard work.