Payoneer is very safe to use!
2 things that you have to know about Payoneer.
1. If someone pay for you on payoneer, and after you deliver your service or product, he will write payoneer that in mistake instead of 5000 he wanted to send 50usd, so payoneer will put a temporary hold on the transaction, and will send it back.
2. Sometimes Payoneer put a hold on your account, and will ask you to prove the source of money. In that case you have to provide either bills, or printscreens of your sold products. (With amazon its easy, as you download it and submit it in one minute)
I use my payoneer since a good year, and i never had any problem with them, expect once someone took back the money after i gave him the website..