I've had quite a few low and 0 feedback buyers. Unless they are phone verified, then my blocks stop them. Most I've found to be great buyers who pay within seconds of the auction finishing. A few I've had to help with a couple of things, but I don't mind that.

One lady wasn't sure how to pay and she wanted to use bank deposit as she didn't have a PayPal account. I talked her through it, but she still couldn't work it out. She started to really panic thinking she'd be labelled a bad buyer (it had only been 24 hours!) so I talked her through PayPal (both as a guest and creating an account). She then paid straight away using PayPal. I told her if she needed help with anything else, she only had to ask. She asked a few more questions which I answered. She was so grateful I had taken the time to help her. She left glowing feedback and his since bought a few other things.

Most of the 'issues' (if you could call them that) I have with low and 0 feedback buyers is convincing them that it's OK to hold off payment until they have finished buying. They want to impress, so will bid on a few things, then as each auction finishes, they pay straight away. 

Most of my non payers aren't low feedback buyers, they are people with much higher feedback scores that should know better. Some have even been sellers themselves, with active listings, so there is no excuse for not getting reminder messages.

Just remember if you do have a non payer, open and close a case and add them to your blocked buyer list. By closing the case, you are helping all the other sellers who already have blocks in place, by giving the bad buyer a strike.

I'm sure your 0 FB buyer will be just fine.