Chris I love the methodical approach you provide here. As I read it allows me to easily identify what I have already done or still need to do. My only hiccup is Bridgy Publish.
Everything that I have read seems to state that this is easy or seemingly obvious. I registered with Bridgy years ago. I then had issues attaching accounts to Bridgy Publish.
I probobly should document this properly. Always thought that it was me, so turned to other plugins, such as IndieWeb and SNAP.