The only things I like about any of the PT is the look of the pod racer vehicles and casting Ewan McGreggor as Obi-Wan. But I hate the pod race and PT Obi-Wan.
So, In my opinion, you're gonna have to do quite a bit more than change Jar-Jars voice to "fix" these films.
Honestly, I can't think of anything from the PT I'd wanna keep.
So, my post is useless.
As usual.