I joined FaceBook too recently, at my sister's request, but I too use a fake name (actually a business name) and a face DOB and I have almost no personal info in my "profile." My family and real-life friends know what I look like, so they can recognize me from my avatar (and probably from what I post and to whom). For others, if I want to invite them to be friends, I send a message identifying myself.

I'm rarely add "friends" of my "friends" as new "friends" unless I know something about them and have reason to add them.   But replying to people's comments or sharing YouTube links, etc., doesn't seem to pose much of a security link.

The thing I'm very wary of is when someone wants you to participate in some online game or poll or post a comment at some other site.   Generally when you do that you have to add that site as a "friend" -- who will have access to all the info you post. Not worth it to me, so I just pass.

Genie