"In 1997, the shot of Luke jumping down following Vader has been extended by two frames. The next shot of Luke entering the pipe has been shortened by two frames.(1997 Change)"

This is just where a reel change occur, those two frames didn't make it when they produced the GOUT, they are included on the PAL version of the disc however.

EDIT:

"In 2004, blast fire from Ion Cannon is white.(2004 Change)"

"In 2004, blue square above switches is now black.(2004 Change)"

I can definitely see color in the blast fire and blue in the button, this is just how things got their look and appearance when the worst colortiming of all time got applied and approved by George Lucas. It affects everything in the transfers, I seriously doubt they sat down and decided that this blue square should be retimed so it appear dark blue, it's just how everything down to every minor detail gets affected by the new colortiming/fuck up. But if these kinds of things help people on this board when they work on their edits, I can see why you list it.