Yes you can do some or maybe all ki exercises like a trick. If you do it that way then you've missed the point.
As for kicking when some students are trying to lift you the reason again is mind control. You just added another degree of dificulty to the ki exercise. It is hard enough keeping both feet on the ground with two people trying to lift you just try raising one leg up and stay centered. The other way of practicing this is by allowing them to pick you up and then you center and sink back to the floor.