Personally a lot of what I feel they could do would be to fix some animations (looking at you mirage dive, fang and claw), but also just make life of the dragon much more exciting to build to and use. To me, it's just projectile vomiting red 3 times every minute or so with a very exciting dive during it. Though they could also prune out some abilities (again, looking at you mirage dive, fang and claw), and retain the 10 GCD full structure with a not as awful looking and (potentially) better finisher by giving drg penta thrust. But that's just the FFXI player in me missing that ability.

Oh, and make life of the dragon more exciting than just a super-cool-amazing-and-powerful dive followed by 3 rounds of projectile vomiting because you twirled so much in the air that you can't hold it in anymore. Just my thoughts.