Well at least on the first point, nonreversible transactions are extremely desired in the porn market. A constant uphill battle for payment processing is that people spending money on porn sites often have "regret" (or, less charitably, they chargeback when their spouse finds out). I believe this is the reasoning for Stripe not taking adult stores as customers. While it isn't consumer friendly to get rid of chargebacks, it's something that would help out these sites a lot.