The Chinese theater thing is a myth. So let's put that to rest.
I don't personally hate the hat, I just hate it's location, what about moving to to the front of the park, outside the turnstiles where the banner is with the film pieces?
One thing I would like to see, if you are planning on doing a HUGE park-wide DCA style renovation, I'd love to see some modern celebrities added to the Footprint Area outside GMR in a re-dedication ceremony. That's all I would do to change the exterior of GMR.
As far as a the Interior of GMR, I would spend most of the money replacing outdated Animatronics. Imagine a New Wicked Witch, a gangster car that work's constantly, and better faces for the celebrity guests! That's about all I would do. I think it would also be a great opportunity to replace the Footlight Parade, Fantasia, and Tarzan Segments. And of course update the finale film as well, and decorate the room to look like a movie theater.
I think the store layouts are fine, and the exteriors still look great. I would absolutely not like an electronic wait time board because it's out of theme, Hollywood and Sunset take place in the Golden Age of Hollywood, Remember.
If you consider adding anything, I might consider something like Cinemagique. Another ride that celebrates movies in General.
Anyway, that's just one person's opinion off the top of my head.