You raised a couple of good questions and deserve my answer.
Re people on the boards who actually know each other, my guess is only a few of us do.  I'm lucky, in that I've personally met and spent time with a lot of them, including mrfisher and GaGambler, as well as ladies like Kendall Lynn and Devin Davette, whom I count as friends.
As for PMing, it's ironic that the object of my mirth abuses his PM privileges grossly.  When he gets upset (which is often) he bombards you with PMs complaining about whatever he doesn't like, to the point of making threats.  The last time it happened he actually lied to me in a futile attempt to upset me to the point where he could report me, I'm sure.
So, yes, I know what it's like to be stalked with PMs.
Have a great day!