Get rid of the “Observers” group
This may be a bit controversial, but I reckon getting rid of the automatically created “Observers” group would be a good thing.
I don't really understand what it adds to the UI (instead, maybe, a bit of unecessary complexity), and it doesn't seem that all the contacts that have subscription to but not from me are put in this group.
This may be serving a specific purpose which I may not get (in which case I'm glad to get clarifications about it (; ), but I think the roster icon with the question mark already fulfills this purpose. Without the need for moving contacts to another group, that is.