I'll say up-front that I don't do weddings - but I do shoot some fast-moving events where I'm regularly changing from inside with flash to inside without flash to outside without flash to outside with fill flash.
In that sort of environment, I have one "memory bank" (I'm using a D3s but it's the same principle as your D7000 with "U1/U2") set up with Auto ISO enabled, shooting in Aperture Priority without flash and varying the aperture depending whether I'm inside or outside and what DoF I need. Another bank is set with Auto ISO disabled for use with flash - either in Aperture Priority so that I can set the value I want or sometimes in Program when speed really is of the essence. I don't have full AUTO on the D3s, but I wouldn't use it if I did because it robs me of some control.
Everyone has different preferences - I suggest you put some more thought into how to best use the control options on the D7000 to fit your way of working. From what you say above, I'm not sure you have yet found the optimum configuration - but it should be there somewhere. However, I doubt you'll find one which allows you to switch between flash and no flash without altering something on the camera too. Automation is great, but the photographer always needs to think about what they are doing and change settings accordingly.
We're drifting a little from the discussion topic of Auto ISO, by the way...