For what it’s worth:
After re-watching the movie recently, here’s my own wish-list of changes (with hopefully most of the points already covered in this thread omitted). Apologies for the length and for any repitition.
TATOOINE
Undo pointless inconsistent Blu-Ray changes such as the door to Jabbas palace being much larger on the outside, but still the same size inside.
Fix the Luke hologram to match the rest of the saga (desaturate, blue tint, add scanlines).
Have the Gamorrean guard strike the tentacled beast in the cage, rather than miss it with a dull thud.
When Jabba knocks Threepio down make Jabba actually strike him rather than Threepio apparently doing a twirl and falling over for no reason.
Have Luke somehow make use of his lightsaber during the battle, rather than just swinging it like a nerf bat.
Even if the lead up is done in a less silly way, still have Boba Fett end up inside the Sarlacc.
Remove the Sarlacc burp gag. One per movie is enough.
Have the chain dig more deeply into Jabba’s throat when Leia’s pulling it.
Don’t re-instate the sandstorm. The current pacing works well at that point.
DAGOBAH
Keep Luke’s visit to Yoda after Tatooine rather than before it. Luke needs a reason for being away so long - his friends.
Have Yoda say “Luke” less often.
ENDOR
Don’t have the scout’s speeder turn corners while he is looking backwards.
Fix or replace the speeder POV shots where the forest can be seen running out, as the footage approaches a clearing.
Keep the scene with Leia and Wicket. This is likely the first instance where an Ewok has been shown kindness by a hitherto mysterious and cruel human race, and a key to getting the Ewoks’ cooperation (even if they still needed a golden man to levitate).
Translate the lines “Yes that’s wise” and “Nice and short” into Ewok-ese.
I think the dialogue in the “I’m sorry”, “Hold me” exchange is redundant and the scene works better without it.
Keep the Ewok traps for the AT-ST’s, but have them trigger before Chewie hijacks one. Currently it looks like the Ewoks could be trapping Chewie.
Fix the terrible effect of the shot AT-ST that, after exploding quite well, quickly cross-fades to a static model of just the legs.
Maybe a little hard to fix, but if possible remove Han’s inappropriate grab when Leia is shot.
DEATH STAR
Make the Death Star bridge bigger, with more consoles and possibly a corridor. Somehow it just feels small, possibly due to lighting.
Fix the blue button pressed by the Imperial operator when Vader’s shuttle is granted passage, which is clearly just a painted square. Have it react somehow by being depressed or lighting up.
Enhance the display off to the side in the throne room, which has pictures on it early in the film but later is blank.
When the first capital ship is hit by the Death Star laser, have the nearby ships react in some way, being tossed by the shockwave or at least taking some damage.
Add more sparks to Vader’s suit as he’s carrying Palpatine to show his suit is now useless, maybe even blow out the chestplate.
Make Palpatine fall a bit further before exploding, making it more apparent he hit the bottom.
Straighten Vader’s bent wrist when he’s leaning over looking down into the shaft.
As the Death Star explodes, make the transition from space POV to Endor POV better somehow. Currently it’s a bit of a letdown when the music hits the high note there isn’t really a visual spectacle to match it.