With enough money thrown at it, there are so many things that could be corrected and made better.
Like when they step foot on Shakaree, everyone sees a different world (Sybok sees the most beautiful garden of Eden, Spock and McCoy see something else, the people on the bridge see something else, and Kirk sees what was in the final film), and we then settle for what Kirk sees. And what Kirk sees could be enhanced to look more alien.
Digitally replace the deck numbers and make slight re-edits, so they don't go up 70 decks, just 12.
Show Sybok having visions of Shakaree and the God creature there earlier in the film.
There also was that fan edit on Youtube that, when Kirk climbs the mountain to escape the God creature, added voice overs from his past, including his "I've always known I'd die alone" which truly elevated that scene.
The filming material is all there for stuff like that.