What would happen if you join all your lens bits and pieces together?

Playing with lenses...what happens when you add three extension tubes for macro, to a Canon EF II 2x Extender, to a Canon EF12 II, to a Canon f/1.4 70-200mm telephoto lens? It becomes a humungous macro lens, but with the advantage that you can be between six and twelve feet away from the object you are photographing!