If there are specific people you think you might offend, you could create a custom friends list. I'm not keen on that as if they find out it exists, trouble could be caused, and I would feel vaguely guilty about the secrecy involved. I think it's legitimate to discuss these things so long as you can do it without giving details which reveal the identity of the people involved. I may of course be saying this because I'm perfectly comfortable with the gray areas of my past turning up in your blog, just so long as my name isn't attached to them in some way. It's a tricky one.