I haven't done rock concert videos but I've shot some fairly large production hula shows with Lumix gear - lately two GH4s on tripods. Having two cams is a huge plus, of course, because I can set one camera wide and use one to follow the action.
Shooting one camera I would definitely shoot 4k, frame the whole stage, and leave it there. I would use manual focus to prevent hunting. I would use manual white balance, set to tungsten or about 3500 Kelvin, to prevent color shifts when stage lighting changes. I would use manual exposure or shutter priority.
Then I'd deliver in 720, which lets me zoom in substantially without any loss in quality. And once I'm zoomed I can pan.
The "180 degree rule" for shutter speed might be a little less than a rule. It's based on traditional film technology, and the details of digital imaging are quite different. It's worth a lot to do plenty of test shots to learn how different shutter speeds change the image. Of course, a slower shutter increases motion blur, so there's a definite lower limit, but some folks prefer something slower than the traditional 180 degree choice.