Right now my focus is on testing the app and trying to get some understanding of how the code works.

Enabling federation makes sense because I want to be able to test and study how it interacts with other instances.

If I purge the install and reinstall, how does that impact the identity of the server to other instances?

Obviously the users, communities, comments would all get removed…

Is there some kind of encryption key that identifies an instance? Or is it the domain name alone that does this?