A feature that I would like to see is an option backup/export the server configuration and be able to restore the configuration to the same or another Plex instance. It should be able to export to a single file and restore Plex from the file.
i.e - I am in the process of moving my Plex to a new server and will like to keep all the settings, watched list, etc on the new server. I have found a walk-through or two on how to do this manually, but it should be a simple web based option in the Plex GUI to do this.