Doubt this is possible, considering the payment processor and the customer's bank are separate entities. Although 2 factor authentication for credit cards kinda exists in the form of 3d-secure, but even that's really flakey in terms of adoption (merchant, payment processor, banks).
> 2. Accept adult-content payments, but don't release the money until after a chargeback window (e.g. 60 days), thus isolating the credit card from any risk.
chargebacks can be initiated up to 120 days from time of purchase, so that's quite a long waiting time. plus it does nothing to prevent people using stolen credit cards to get stolen content. why pay $50/month to access "patron only" content when you can buy a stolen credit card for $1 and use that instead?
>3. Pass-on the chargeback rate (I imagine it can't be higher than 20%) to those wishing to do business as a cost-of-business fee.
this ignores the fixed chargeback fee ($25?) that merchants get hit with when a chargeback occurs. what will you do when a carder sends all his stolen credit card your way?
finally, doing any of the above costs support reps, engineering time, etc., which only caters to a small % of potential merchants. so you end up with the situation we have today. "mainstream" processors who handle the 99% of non-risky merchants, and a few select payment processors that target the risky 1% niche.