I have been using Lemmy for 20 days, at first I opened an account at Lemmy.world because you can join without writing a text and waiting approval. I have been enjoying the experience overall but despite the admin teans best efforts Lemmy.world has been experiencing some serious performance issues. If you want to avoid that join a smaller instance, preferably hosted in your country. I joined discuss.tchncs.de today and everything is so much faster it has added benefit of being able to see beehaw.org posts too. It will improve not only your but all other Lemmy.world users experience too.
What do you mean? Why would you need to migrate your account?
In order to switch instances hosted on a different server, but keep your account history such as comments, votes, posts, saved posts, etc.
Only way to switch instances right now is to make a new account from scratch on that instance.
But you can still view and interact with all content on any federated instance so why would you need another account?