I don't think the queue needs to know they are a group, the user can just select multiple entries and do what they want.
Sounds reasonnable. In the queue, album art and artist name should allow for easy human recognition of groups in most cases anyway.
Multi-track selection is something we've been willing to bring for some time, with keyboard controls (shift, ctrl) in addition to pointer support. We would like to bring this basically to everywhere there is a list of tracks: album page, playlist page, queue… I can't tell yet when this should be available though.
I always tend to over-complicate things!
I feel you!