Now I have no idea how intensive these changes would be since I have no experience but they are just suggestions and quality of life implements that would be nice
For CCs:
Hitman and cop options are toggleable and can be on the same CC
A dedicated button to buying weapon slots to not need to use all the slots you have available
For custom weapons, list the gun they reskin
Add default/vanilla models that aren't already in list, i.e Master Chief, Assassin, Weapon Modifier
For everything else:
A way to check if you have a certain XP category checked and to see all progression
Ability to stack locked inventory slots if it's the same item, i.e drugs
An /invholster button in your inventory/C menu
(Based) Cheaper accessory items
Double XP events or ability to give everyone double XP
Ability to close/minimize party menu on the side and a better way of seeing other party members