The way Lemmy works right now is you search a community in your instance for it to then get shown, so you need to first discover that community from elsewhere. With that in mind, what are some growing communities that you discovered that could get some more love?
Yeah it does, when you delete some content it creates a “delete” activity which is sent out to all the servers that content was shared with. Those instances should remove the content on their side too, of course there is no way to ensure the content that has been shared is deleted, but activitypub does have a mechanism to delete content that has been federated.