IMO you shouldn't try to replace the web with gopher. For me it had a single purpose: share files. If you want to make a payment, you shouldn't use gopher as it's simply not meant for that. It should probably be a different protocol for that, something peer-to-peet rather than centralized like gopher is ?
As for encryption, there were some proposal to add it to gopher (and working ones!). IMO the best way would be to do encryption at the network level rather than at the protocol. But we're far from here :)