If you're building this to be a generally useful mod, keep in mind it is non-standard to include a copy of the player window within the group window, so you might want to include ClickCures in your Player window. If you're showing detrimental icons anyway... it shouldn't take any extra room.
The large percentages shown in your mockup would probably need to be a custom window or two. You can most definitely pipe your health and power percentages to a custom window and as lordebon said, it should be possible to create a menu or click scripts to show groupmember data instead.
BTW, you might want to check to see if your existing Player window is resizable. A good deal of the custom Player window are, and this might solve your "Small Bars" issue
Hybrid Mode
