The only time I've checked the PDA section is to check up on Morgan's Update by Jamie. Or when someone on Live Chat said something was in their PDA and gave a page number. I don't have the patience or time to wade through everyone's diary, even though there are those with whom I would like to keep in touch.
I usually only check Pictures, Main, and Chit Chat. I like MQ's suggestion of a pm to members who violate the rules, but this might involve too much of your or moderators time. As far as how to handle floods of certain topics or those getting out of hand, no idea. It will happen. And I'm sure however you handle it, there will be some who consider it the wrong way.
I would like to say thank you for having a place to come and communicate with other people who like to quilt. Good luck.