Restoring a deleted scene: I can’t help you with that, even the most gifted editors here can’t do this. Most RotJ and Prequel Deleted scenes, though, are actually good enough quality that they’re usable.
Making Transitions Smooth: Really depends on a lot. What scenes? What’s happening? What’s smooth? How’s the transition happening?
Redoing music & sound effects, and removing music & sound: The Blu-Rays come with multiple tracks. If you’re using them, you can just mute one track for a certain part of the movie. If you’re using some other source (like Harmy, for example), I’d recommending just putting in Blu-Ray audio around the change in question.
Color correcting to the OT: I already know you know more about this than me
Actually, the blu-ray audio tracks do not have a dedicated track to music/sound. I would recommend just building/inserting as much custom sfx as possible for the desired scene and then adding the music. Then for dialogue, you can isolate the center channel and maybe do some noise reduction on it to get rid of even more music.
That is what I have discovered usually is the most reliable way to replace music seamlessly.