The gender swap/underwear issue could be solved very easily. Make all underwear items for all genders, just as they plan to make them for all races, with (obviously) the displayed model being different depending on the character's race and gender.

Or, if for some weird reason that's not possible, just force the underwear to be unequipped on a character whose gender was changed, and put in an NPC that lets you trade underwear for that of the opposite gender. I'm sure the writers and artists would have fun designing an NPC that specializes in that sort of thing. They could have the NPC sell knee-high socks, too.