@steeminganarchy has addressed many of the living at sea questions in his seasteading fiction.
There's also the issue of citizenship. What happens when crypto city-states start popping up everywhere and people start abandoning the legacy system entirely and try to start over with a whole new governance model?
This is probably closer than some people realize. Estonia, Malta, Portugal, and a few other countries are becoming more and more crypto-friendly. That trend can only increase.
The real question may be What happens when the Petrodollar system collapses?
The elite takes over Bitcoin and then pushes their corporate shitcoins on anyone ignorant enough to believe them.