Currently, there's a lot of missing stuff from GTA/GTA Online that aren't on the server and also some missing features that I believe could be beneficial to the roleplay community:
Saving outfits system, maybe a app on the phone? But custom preset outfits would be cool, and also if clothes could become free or just a set price for each outfit you have would be nice, theres no reason for clothes to cost alot as theyre a part of rp.
Missing GTA Online Clothing/Tattoos
Ability to change character makeup at the barbershop and adding the missing eye makeup for characters
Ability to stack tattoos on top of each other for example having 2 different chest tattoos, and also the ability to remove tattoos completely like you can IRL with laser tattoo removal.
A /hairtie command so you can change your hairstyle on the fly (maybe make it so detailed RP is required)
These are the ideas I have at the moment, but feel free to suggest yours if you have any.