Is there a way to register chat channels, and when i search for channel get a list of channels even if there is nobody on it?
What do you mean by chat channels? If by channel you mean room then the answer is yes. You could create persistent rooms and they can be discovered even if the room has no occupants.
Will the group chat rooms be visible in the admin ui in a future release? Are the rooms also planned to be configurable?
We don’'t have that feature in our roadmap. However, you have in the API everything that you need to build your own JSP pages.