Here are my answers:
Enjoy having the opportunity to talk with other members who might share similar interests.
Not too often, probably 2 or 3 times a week would push it.
I don't feel like I've got enough blog-worthy stuff to say.
Occasionally, some are pretty fun.
Almost 5 years; 7750
Not sure, I already post a lot
For me, I don't think the forums are hard to find, mainly because I've been on the site for so long. With how the front page is currently set up, new users might find it too hard to find the links to them at first.