I think this is important because when casting a channeling spell, we need to cancel channeling so that we can use other skills. We need to use the skill and press the channeling button again. It causes huge loss.
It’s usually posssible to keep the channeling button or key down while activating (or reactivating) other skills.
It’s a good idea to use a key for force move, so that you are not relying on mouse click to move and also a key for force stand still.