About Scenario 1: Please read our FAQ: 8. "What if the buyer invalidates a transaction without any reason?" https://savact.com/menu/faq/

About Scenario 2: A serious seller should, of course, always check if he is about to sell all his goods to a single house address.
So Scenario 2 cannot happen using that argument. If the competitor would try to do it anyway, he would run into a huge risk that all his funds will be lost and neither receive any goods, because the seller caught up to his scheme.
You could compare it to PayPal. Using PayPal, the buyer is almost always in the right if you buy something in Asia from Western countries. Even so, sellers have no problem offering PayPal as a payment method.

The sellers would increase their sales by minimizing the buyers' risk.
Please remember, this is a system for anonymous payments. Trustees target another market.

We would appreciate if you could also have a look at our applications for binding votings.