This all seems a bit confused. This has nothing to do with encryption. ProtonMail cooperates with law enforcement to track down users, but they do need a proper legal process. They won't just release user information on a simple request. They do have the ability to capture IP addresses.
ProtonMail is accessible over Tor, but they don't allow registration/verification over Tor.
ProtonMail is accessible over Tor, but they don't allow registration/verification over Tor.