This looks really quite amazing. And absolutely brilliant documentation - this has my vote for the best documented Plugin in meta.discourse.org!!
Have you considered extending this so that it also covers topic lists too?
I often find that it would be very helpful having per-category or per-tag collection of links. An example is a private category dedicated to specific group, which also uses some other tools (such as a few folders in Google Docs, a local government portal, an associated chat channel, and a group inbox). It would be ideal to have category moderators control over it.