Awesome. :)

I can't speak for your original intention, but this is the feeling I had when watching a certain scene. Luke sits in his X-Wing cockpit and flies to rendezvous with the fleet. He gloves his prosthetic hand. Reminiscent of Vader's mechanical body. And Luke has this odd smile while Vader tries to communicate from light-years away. The edit gives the impression that the young Jedi is starting to crack a bit well before he ever steps into the Emperor's throne room.

What causes Luke to snap in this theoretical edit?

Nothing in particular triggers his outburst. He sits in the shadows, losing to fear and anger. The dark side is thick like fog in the throne room.

Drag this small part out a few seconds, add heart-beat and hyperventilation sound effects, cut Vader's line. . . and then abruptly END those sounds. Then he snaps. Luke's "No!" could be replaced by an enraged scream.

Problem solved. The structure of the battle is intact. How many hours of work would that save you fixing a structure that's already good as is?

Could someone throw together a rough example of this? I'll try to get Windows Movie Maker working on my computer.