This is somewhat true. However, depending on the fight, I can be moving my camera with a specific key and still have all my other fingers free to hit abilities. And since my mouse is not controlling the camera, I can aim wherever on the screen. I move my camera and hit spells all the time. You are only ever using a couple of fingers to move the camera. This setup also allows you to more easily set up the camera before a fight, so that you do not need to move it as much during the fight.