I don't have much call for most of the camera system, and my battery life on my Pro is just fine. I have plenty of chargers typically, and for emergencies or times I know I'm going to be out I could potentially get the battery pack.
I basically never use cases on my iPhone, and at most will maybe use an ultra-thin one or some sort of structure adhered to the plateau just to make it flat across so as to not rock on a table.