Wow - no chargebacks? Do people buy crypto coins this way?

This is a huge benefit to the merchant if it's true. There's no direct benefit to the customer, so you have to overcome that somehow.

Not 100%. This removes chargebacks due to theft (or I didnt make that transaction) I believe, but people can still chargeback for many reasons - disputing quality of product/service being the biggest headache, product not being delivered (or supposedly) another..