Yes, the one of yours is much better. But I only did the one of mine in about 5 minutes, just to demonstrate the basic idea. I noticed that you had the same problem while adding 'Mouse Button Down' event to the "slider-knob" actor as you can't use empty script. But instead of your "x=x;" I used a comment "//no script"
Maybe Makslane could add a "draggable" actor property. If checked (or set to TRUE in script), the actor would be draggable. If unchecked (or set to FALSE), it wouldn't be draggable. Then maybe som new events, like "Drag" and "Drop". That would be neat.