I think the best thing for sellers to do is just file a NPB alert and for the sake of sanity use the tools provided by ebay to safeguard yourself.
The tools I suggest using;
1. BIN/BO with immediate payment to deter NPB who hit BIN's
2. Set an auto filter for auctions that bidders with less than X feedback can bid. Also use the filter that no bidder with X amounts of NPB cannot bid on your auctions.
Ive set mine at 2. If you have 2 NPB dings on your ebay user ID, you cant bid on my auctions. Ive had 3 in the past 4 months. Im okay with that.