I would really like to be able to change my characters' hair style/colour, add scars, facial hair, maybe the option to change face and eye features slightly, perhaps even the undergarments? (Tarutaru undergarments are so grotesque)! Also, another problem with Tarutaru is that males and females look identical - especially with head-gear on! I think adding some customisable options would really help keep things a bit more interesting, as well as helping our characters look more unique and personal to us.
This could be done in a similar way to the Monster Hunter customisation options, where there is a hair customisation menu in your room, with a choice of hairstyles and colours to choose from. You could even make it so you have to complete quests in order to unlock each hairstyle/customisation and once unlocked, can be accessed via a menu in the mog house.
Alternatively, a beauty salon could be implemented where you pay gil to change hairstyles/colour etc (I can totally picture a very flamboyant Galka as the stylist lol), or as a last resort, make it a payable option, where you can buy a new style through the playonline service. I would prefer that the option to customise was "free" though, either by completing quests/events or by paying gil to an NPC.
This has just come to me as another option; you could even make job-specific hairstyles/customisations, something that compliments the job and equipment.
I know there are a lot of people who feel the same way as i do on this matter and I really hope that this is something that is plausible and could be considered as a viable option.
Thanks for taking the time to read this, and anyone who agrees or has an opinion to share, please feel free to add to this thread ^-^