The Emperor should be a hologram when declaring the Republic is now an Empire. I like the idea from the original ANH adaptation (I think), about the Emperor locking himself way from the masses. It would also show the Senate how “dangerous” the Jedi are. I feel he shouldn’t be seen in the flesh again after the Jedi attack, except when with Anakin/Vader.
It would be cool to see Star Destroyers added to the skies on Coruscant, really emphasising the miliary presence.
I’d love to see a mock up of the Jedi Temple with greenery and vines growing over it.