Other than the Grey Prince, has there ever been a hybrid of two different races before.
That was just because he was the first known vampire hybrid.
The child always take the mothers race, so you wouldn't really know if someone was a mixed race.
Back to the topic, I'd like to see a Bosmer try and take the throne.
Especially as an ingame book detailing his failed attempt.
But the again, Martins kid would also be the son of a devout priest who ultmately sacrificed his life for his people, daedra worshipper or not, the fact tat he gave up his old ways to become a priest and then ultimately saved tamriel speak alot for his character.
In short, Martins kid comes from a good stock.
Not if the kid came after Martin gave up his daedra worship.
The mother more than likely would still be a daedra worshipper, and would've raised the child as a daedra worshipper.