Dynamic Music and Job Themes
As the title suggest adding dynamic music and job themes to existing fights and future fights would be a cool addition to the game. The dynamic music portion of the suggestion could be tied to how a party is doing in a fight. If you are doing really well layers and intensity gets added, where as if you are doing poorly a basic version of a track plays. As for job themes, these would be handled by a toggle like mount music. You could turn it on if you wanted to override a fight's combat theme. Plus it would add more character to the jobs themselves.