Multiple servers... Even on reddit I'd want a separate user for separate groups of subreddits... (at least for posting, for reading it could work as you describ

Multiple servers... Even on reddit I'd want a separate user for separate groups of subreddits... (at least for posting, for reading it could work as you describe, probably client could authenticate at one server, but connect to others to get the data). Just make sure that the client can support this cleanly/efficiently.