Ok, so I tried it out. First, I had to play with my FT preferences to set auto subscriptions to "No email notification" (was on "Do not subscribe").
2ndly, it's not exactly what I was talking about... while this just unbolds the threads you've visited, my suggestion completely eliminates the thread from your list until a new reply is posted. It also only eliminates it if you've actually visited the thread, so it will stay on without timing out.
Oh well, gotta make due. Thanks for the advice though.... still made my FT experience better ^