1. Not necessarily. I may be that someone is shy or doesn't want anyone to conclude that it must have been "them" who posted something. But I admit that can cause a problem if someone is shy and has a nasty comment. Perhaps I'm no help on this one, but I think I have some valid points.
2. I think posts should be related to our community and events.
3. Wiping the board clean quarterly?--if there's something we can scroll back to and learn from, no. If it's about an event that's past history, yes.