For me, federated networks make a lot of sense when you want moderation and admins. Having a lot of little places with centralized control that can all talk to each other is much preferable to having 5 giant shitty walled gardens.

If I'm going to talk to a friend or a small group of friends directly, then I don't feel a need to have a centralized authority in the works, which is why I'd prefer peer-to-peer for that kind of communication.

Those are just my preferences though; good luck with the project, and hack on!