We sell a ton on ebay/amazon/etsy.
1. why block countries? I cannot show proof of delivery using USPS mail. Some coutries are much higher frausters then others. We block those.
2. Buyers cannot leave neg/neutrals. Its been like this for along time
3. Cherry this is how its gonna play out. Your gonna say your right. They will say they are right. Ebay is going to tell them to send the item back to you for a full refund. They will have to pay the ssh back. Paypal will hold the money until they send it back our close the dispute, i beleive once 30 days have passed if they do nothing it closes automatically as well (may be 45). When you get the item back you will need to close the dispute and the money paypal already has will go back to the buyer. If you do not refund it paypal will automcatilly if they see the item has been delivered by via confromation. BUt that will indeed be how it plays out

Been thier done that.
Amazon is just as bad, their are tons of whack jobs their wanting something for nothing as well. Point, no mater what platform you sell on your gonna loose as the seller unless its your own website and even then its tough when it comes to charge backs and people today know that.