I missed that!
Your ideas sound like more than can be done with a fan edit.
I guess I am thinking smaller. If you rrally think about it, there never was a true sequel to STAR WARS. Empire throws the whole Vader =Skywalker thing in there and that just isn't where Star Wars was going. It wasn't even a "twinkle in George's eye" until the fourth draft of Empire.
So I'm musing whether a direct, by the rules of STAR WARS '77 sequel/prequel could be constructed fom the prequel material.
That would mean no references to the other sequels, Yoda exists only in the prequel, Skywalker is a loyal friend and Vader is a talented, but ambitious pupil of Obi Wan.
But how does Vader betray and Murder Skywalker? With the footage that exists? Who in the cast could become Skywalker?
If Darth Maul was Vader, and Skywalker was Qui Gon? ...No.