Father versus Son never actually was my idea about the Old and New Testaments. It comes through a bit like Enlil versus Enki, if you see what I mean.
Then, having nephelim tainted genome is not in itself a death warrant in God's eyes. Jericho may have had no or very little Nephelim blood, still it was destroyed. I think Carthage in Hannibal's and his successors' time was human as far as genome goes.
But Tanit cult was clearly giant behaviour. That's a death warrant
Conversely again, a certain Reprobus who had served both a human king and Satan, who was nine feet tall, I think if the general lines of your research are correct or some of them, he would have descended from Ham's wife with a lot of her nephelim ancestry, but when he saw Satan cringe before the mere image of a cross with a crucified man on it, he knew the crucified man had to be mightier than Satan.
He later carried the Christ Child on his shoulders, St Christopher was yesterday.
II) 7:47 and the Sons of Seth scenario.
1) we cannot say that Nodian monarchy continued undivided and unmixed up to flood. 10 generations Adam to Noah, 7 Adam to Lamech - and a situation ripe for dynastic rivalry (confer Mahabharata)
2) if Sons of Seth married Nodians, they might have not continued as a separate people
3) look at today's society ... how far can Christians go along with it without counting as apostates? How much "flesh is corrupted" by late marriages in a sex maniac world? Abortion?
III) [A bit later:] Nephelim tainted genome impossible for Messiah?
Was Rahab from Jericho nephelim tainted or not?
If she was not nephelim tainted, probably neither was the population of Jericho. Yet it was destroyed.
Unless you say she was only human among giants.
But if she had ancestry from Ham's nephelim tainted wife, then so has King David and Our Lord Jesus Christ who descend from her. Confer Matthew chapter ... 2? 1?
Your line of thought may have originated as one Samarian excuse for rejecting the Davidic line. Or in a certain horror movie from the eighties.
But if Jericho was destroyed for deeds rather than for seeds, like Carthage, then maybe you should take another look at Cortez in Mexico and at Simon of Montfort taking Albigensian strongholds.
For introduction about Albigensian evil, I recommend "The Night's Dark Shade" by Elena Maria Vidal (her pen name, real name of her grandmother).
Amazon : The Night's Dark Shade [Paperback] : Elena Maria Vidal
my comments on second half:
... on Diverse Details in an Interview Skiba/Ulrich on Sept 11, and in Skiba/Doug dialogue May 23