I always thought a lot of the shrink was due to people disagreeing over political issues. I just stop reading threads that start getting too "religious" I always though instead of just ignoring those threads like me people stopped coming all together.
Ever thought of sending an email out to everyone registered and saying hey we're still here ?
I hope no one feels that just because I host the site, I am somehow exempt from following the general guidelines of having a polite and civil discussion.
I doubt anyone thinks that, when I see a post from you I don't really even think about you hosting the site.
If you want to restructure the site I would suggest just having announcements, for sale, general, and empeg. I would guess many of the posts get ignored in the less popular sub forums because they are so infrequently posted in. When there are not a ton of posts the it's better to have less forums so the posts there are get more visibility.