Mankar Camoran is royalty - his descent from the Camoran dynasty is probably more legitimate than Uriel's descent from Tiber. The stone requires royalty, so when it can choose between the two...
Yes, the stone requires royalty though the whole A spawned B spawned C relationship has little to do with it. The reason for this is two fold, in some four thousand years, almost everybody in Cyrodiil should have some blood relationship with Alessia. In this case the main quests could be ended by finding the first beggar and crowning him Emperor. At the same time, history has plenty of examples of random, unrelated people picking up the Amulet and becoming Emperor or Empress.
The only thing left now for royalty is to act like it.
So Mankar and Martin are both potential Emperors.
Pretty much. Hence he's glad to see the Champion show up in paradise, that means it's all, almost done. Though considering some one pegged Martin as Akatosh, Mankar as Lorkhan with the Amulet as his Heart, the player ends up being Trinimac leaving Mankar little chance.
Lorkhan/Akatosh waveform collapse.
No. The Camoran dynasty was from Valenwood - Ayleid exiles, probably.
Yea, it's easier to let go a bit of the races a physical identities and rather consider their appearance in the games stereotyped versions of their cultural identity.