Chevvron, I imagine that the first few points are covered by the ANSP contract for City Tower.
Your subsequent points, well, they're covered in posts above. Digital tower technology potentially gives you the ability to provide more information to the ATCO. But to do that effectively you might need to remove windows from the picture, pardon the pun.
To overlay data on top of visuals, you've got a few methods:
-Plot it on top of a video feed displayed on screens
-Project it on to windows a la HUDs (not viable where more than one person is operating due to parallax.
-Equip each operator with a personal HUD/Helmet mounted display (medical restrictions? Comfort? Serviceability of equipment? How do I know I'm seeing the same data/view/functions as the person I'm co-ordinating with? How is that recorded for investigation? Even more hurdles with this one).