Greyhawk doesn't have a mountain of material if taken in total, let alone for any given race. There's no mountain of material for elves, humans, dwarves, gnomes, dragons, dragonborn, or weasel men from alcatraz.
You can drop an entire community of dragonborn into any spot in Greyhawk you want. I can drop them into the Greyhawk City if I want to. There zero need to find an empty space for them, because the level of detail on the Greyhawk setting is so minimal that almost anything can have communities...
I don't know where you get this from. They have a physical body formed from the essence of gods. They bleed. They can procreate. They are flesh and blood. I don't see a good reason to think that the offspring of angels have no genetics to pass on.
That at least makes some sense as it's about the life of the person. Not covering the phone in my pocket if it's destroyed by a nuclear blast? Not so much.
That reminds me of this kid(we were in junior high) I played with back in 1e. If he rolled really badly on character stats he would announce to the DM that his character would buy some rope and walk to a nearby bridge, then tie a rock to his leg and jump into the river.
And usually someone else has to approve the change.
Many years ago my cell phone company changed insurance carriers and I guess they had to inform their customers of what the new coverages would be, because I received a 30-40 page booklet in the mail. I dutifully tossed it onto my desk and...
You also have to assume that the Aasimar special traits occupy the same space as the other parent's special traits so that the dominance can happen, and you can't end up with both parents special traits.
What you are referring to would only really come into play if say the other parent had some...