Honestly the story/plot wasn't the problem with the prequels - or at least, wasn't one of the top 5 problems with the prequels. I thought the plots were often rather stale, especially the trade stuff in PM...but if the films had a competent script it wouldn't have been an issue at all. Ultimately everyone knew how the three films would go: introduce Anakin, get to the Clone Wars, explain Anakin's descent to the dark side. That was always going to be the arc. How they did it is the problem, not the side stories and subplots.
The excessive green screen, the terrible acting, the lack of any memorable characters, the lack of iconic or even memorable moments, the stale direction and repetitive fight choreography, etc etc etc were all far bigger issues.
So I wouldn't mind Lucas coming up with stories. However what I would mind is Lucas being in charge of the film - because you just know he'd surround himself with sychophants and produce a half assed trilogy.