[Write14u]

Adorable,
As a person who also helps manage a staff, albeit much smaller than yours, I can understand your dilemma. I would definitely take him to task for the rules violations. That's something he has to do right and he put it out there in the open, so it's fair game. The rest ...eh....if he DOES leave, I'd let it be. If he hangs around, it might require a future talk.

And on to FB...
I've had it bite me in the ass, but not from anything work related. First off, I try not to post anything work related on mine, and I hold to some older rules of life, ie, not putting up anything I wouldn't want my mom to see. Yeah, well, I'm not always great at that. But I am conscious that my nephew and other family members are my "friends."
As for the workplace, maybe me and my profession are just weird. Our business is communications -- and we readily use FB for that. If they told us we couldn't FB at work, my executive editor would be the guy most hampered by it. We post links to our stories, to our paper's fan page.
My FB experience started out almost exclusively with co-workers and former co-workers and has grown to family and friends of friends and stuff like that. I love the liberal nature of my co-workers and that I rarely see more than token newpaper bashing (ie, yeah, the industry still sucks right now.) Believe me, when we took a 10 percent pay cut last summer, damn near everyone in the paper posted something in their status. *shrug* But nobody was getting fired over it. The higher ups knew we were getting it without lube.

Definitely a fine line with a lot of things, though. I've found I'm not easily searchable for some reason. Never meant for that, but oh well.