Cause it takes a lot of effort to make a 'fake' facebook profile - I had one and it only lasted a few months before it was locked out pending government-issue ID being sent to them, since I wasn't actually using it for anything more than looking at the occasional thing that required an account I can only assume they monitor for unusual use patterns.
I don't think so, it looks like that might have to be done entirely via the programming API, and you need an application registered to do so (or the access token of another application) because it only works on one application: http://developers.facebook.com/docs/test_users/
You can definitely create a user and then turn him into a test account manually, I've created many test accounts that way. You have to visit a special URL that turns the account into a test account (can't remember it offhand, and I'm not going to post it anyway since if anyone clicks on it then clicks "accept" without looking, it nukes their regular account).
