Last I heard, and this seems to be the case as of this moment as well, only a few accounts are federated for testing (as in, maybe just one?). Mine definitely is not. Of course, this could change at any moment since it's released as alpha.
A botkit is in development, using Fedify for the federation bits. I know of two projects that could have a “bot store” in a way. The first is IceShrimp.NET which is working on a plugin architecture . The second is from Mastodon, a plugin architecture is being created, initially to support quote posts, I think? Not much info there yet. These things collectively could be used as building blocks for your idea.
Last I heard, and this seems to be the case as of this moment as well, only a few accounts are federated for testing (as in, maybe just one?). Mine definitely is not. Of course, this could change at any moment since it's released as alpha.