I would keep the informative posts on the whistle board, flute board, etc. These posts prevent the same things from being asked over and over and over (in theory at least), and are useful to keep around because they're directly relevant to C&F's main purpose.
Conversely, I would allow the posts on the Pub and the PROCTology forum to be deleted after a set period of time (a month, six months, a year, or whatever you decide) because most of them are not really relevant in the same way as the instrument and music ones are (especially the ones that change with the election cycles, seasons, weather, etc. and are then no longer relevant). This kind of move seems like it would free up a bunch of space while at the same time keep the good stuff where it is, no?
I belong to one message board where after a year, all threads that haven't been posted in are deleted, except for sticky threads. And I'm pretty sure locked threads are automatically deleted after a certain amount of time, too. That board has never had problems like C&F has recently had. I don't know if it's related or not. My hunch is that it is, though.
I'm not too terribly well versed in these things, so if what I said doesn't make sense, never mind.
P.S. I miss Rich already.