I had the same problem and never received my order. I have lodged a complaint with PayPal. I predict eCRATER will crater. This seems to be a very poorly policed eCommerce portal. Good Luck getting a refund.
There is no selling limit. Yes, I believe you can sell coupons. Not sure. I have only purchased from PepperzCantina and there weren't any coupons in that store. This site is relatively unknown but it has been around for at least ten years.