Raubhan Aldynn is the true leader of Ul'Dah?

[Caffekon]

snip

I see your point, it makes a lot of sense.
I suppose out of the players sphere (no restrictions) such relationship between the races are rather unusual or even inexistencial in the lore, every real couple I've seen in the game are of the same race, but I've also seen hookers in many points of Eorzea engaging in interracial flerting, but that's all, maybe Square just inserted such flertings for the sake of ambience building.
In the game itself there arent any clues of hybrids anywhere, I suppose for a question of design and to avoid trouble they simply choose to ignore the matter, as I said we don't really need to think deep in a fantasy game.