I get it, this game is 8 years old and if these options haven't been added yet, they probably never will. Still, lower impact on development than making actual gameplay changes. Worth a try.
-The option to turn off all cut-ins and chat bubbles, if not all then at least the ones from players. These are intrusive and sometimes obnoxious during quests. It's sad that I have to block individual players to put a stop to it.
-The option to turn off, scale down, and/or alter the opacity of the "Emergency Code" full-screen alerts. These can really block the action, especially when lots of things are happening at once.
-The ability to move and scale some of the UI elements separately, such as the mini map, sub pallet, weapon pallet, player health/resource panel, and party member panels.
-The option to rebind buttons 1-9 on the subpallet as well as the shift modifiers on the mouse abilities (action 4, 5, 6, backpallet?), maybe on controller too?
-Some more camera options. Further max zoom and/or wider FOV. These options are available for the fixed cameras, but why not the primary one?
-Lock-on camera options. Some polish would go a long way, especially when it comes to aerial combat. Ideally option 1 to keep it as it is and option 2 to allow our character to behave as though locked on, but with a free-moving camera.