Should I set up accounts on multiple servers? Why or why not?
Yes, you probably should, primarily as backup options for when your current server goes down. Happened to me twice.
Should I care which server(s) I use at all? Why or why not?
Probably a bit. You don’t want your server to be blocked by many other servers or be politically controversial (a mutual didn’t allow my follow request from my backup account because it was on a libertarian server). Finding interesting people on the fediverse is kind of difficult, starting with an interesting server can speed up that process. But most of the time you’ll probably be interacting with people who are not on your server.
It seems like routing and identity (in terms of who’s following and going to see your posts) are tied to server. There are procedures for migration, but presumably a dead or rogue server would just lose all your data. Is there a secure export available, that would let one seamlessly restore all follows, followers, and posts on a new server?
There is a method for exporting, but it only allows for importing follows on a new server, but not followers (which I think is technically infeasible, because adversarial users could just declare that everyone is following them now) or posts (which looks technically feasible but hasn’t been done yet).
Yes, you probably should, primarily as backup options for when your current server goes down. Happened to me twice.
Probably a bit. You don’t want your server to be blocked by many other servers or be politically controversial (a mutual didn’t allow my follow request from my backup account because it was on a libertarian server). Finding interesting people on the fediverse is kind of difficult, starting with an interesting server can speed up that process. But most of the time you’ll probably be interacting with people who are not on your server.
There is a method for exporting, but it only allows for importing follows on a new server, but not followers (which I think is technically infeasible, because adversarial users could just declare that everyone is following them now) or posts (which looks technically feasible but hasn’t been done yet).
Hope this helps.