Have you thought about adding in a scene where Vader flies to Coruscant and sees Palpatine at the end, right before the ceremony, maybe using footage from the end of EPII when Dooku flies back (but obviously changing up the shots a bit)?
I just feel that if we're suggesting changes, something that I feel is somewhat missed in the OT is more of the Emperor and Coruscant.
Just thinking this: what if the lightsaber duel in ROTJ had been on Coruscant?