When I have doubts about a supplier I use a cash card (check out ClearCash, Bread, Neteller, etc). Basically it's a card without credit facilities and not tied to a bank account, so whatever you load it with is what's on it, nothing else. Used often by parents to give kids pocket money, I understand.
So, you get one of those and when you want to pay someone you are unsure about, put on it whatever you need at that time and off you go. They can't take more than you have on the card, so your main money is safe.
Downside is that they cost to run: either you pay a percentage of every sale, or a fixed amount a month (you can usually choose to suit your likely usage). I think Neteller has no charges if you use it just for this kind of thing.
You can load 'em up via a bank transfer or by paying actual money at a corner shop or post office.