So let’s take this actual example: There’s !canada@lemmy.ml and !canada@lemmy.ca. They talk about the same thing, but are treated by the current federation implementation as separate instances.
How would you feel if there was a moderation feature to import another federated instance’s community into your own, so that the posts from the other instance automatically show up in the same feed? That way, you only have to subscribe to one community on one instance, but you get content from multiple instances. I’m not talking about crossposting or mirroring/duplicating posts between communities, only displaying the posts from another instance the community’s home server federates with, with moderator discretion.
Your own server is the one through which you interact with all others. You just talk to it, and then it talks to the other servers.
Yup, the domain name is part of what defines your identity. I would expect that eventually we’ll have more interface options to ensure it’s not too confusing who’s who (especially since there’s your real username and then you can also set a display name) but it’s one of those things that isn’t really a problem until it’s a problem.
Deletions in the fediverse have been a big deal in past. The tl;dr is that your “home” server would send out a “hey delete this” notification to all the other servers. By default they will of course do that, but you can see that it’s conceivable that someone could make a malicious version of server software that wouldn’t.
I am not a dev on the project so I am happy to pitch in answering Qs. :)