It's highly dependant on the provider and what he's willing to do for money, even if USA's authotiry there is zero to none. If no legal actions can be taken against the company (if any) behind Warmane, the next step will be domain seizure like they're doing with illegal websites hosted on offshores
2. Domain can (probably won't) be taken down - The registrar who created the domain name is the party responsible for having it removed or deactivated when needed.
It doesn't matter via what third-party the domain is registered, the owner is still VeriSign and USA have full rights to take it down if they want to
3. Payment solutions / accounts can be blocked
Paymentwall is a global payments platform which provides 150 local payment methods, incl. credit cards and e-wallets, in 200+ countries.
San Francisco, California, United States