I agree it would be a good point to implement customization and in particular if this is done in game (barber, tattooist...). It’s fine for me to pay in gils for such services.
Concerning the change in race/sex, by the twelve it will be a pity. I imagine “Hello friend Lalafell… oh Nophica please protect me what a f*** curse! You, you were changed in an Elezen !”. No sorry I can imagine that…
For the name I don’t be sure it will be a good idea to generalize this. Hopefully there are few “out of roleplay” names in this game.