1. Only time I was referred to as Hjalti was doing a quest after sleeping in Tiber's old room at that inn. Other than that I don't recollect ever being called Hjalti.
2. Dragonborn(s) are all called Ysmir.
3. The Dominion banned Talos worship to weaken the Wheel of Convention.
4. I'm willing to bet that the warriors in the HoV do know Talos they just don't mention him in the game.
1. That's what I was referencing, and I was wondering if there was more to his thinking than the fact that you're Dragonborn.
2. Yes, I acknowledged that.
3. Yes, but was the fact that Bethesda threw that in to say how even though you're Talos, they are refuting the evidence? (Assuming you are Talos, that is.)
4. Yes, but maybe they thought that you were Talos, and they didn't feel it would be normal to talk to you as if you weren't who you are.
Like the above said its a gift the septims were wiped out during the oblivion crisis. The dovahkiin was gifted the power to defeat Alduin as (I predict) akatosh divine of time foresaw.
But Alduin is the firstborn to Akatosh, whose goal it was to end the world. The fact that Lorkhan/Shor tricked him into creating Mundus would show that it was an accident that Alduin was meant to fix. Then he sends the Dragonborn. Thus we can assume that either Akatosh changed his mind about ending the world, or that he only wanted to postpone it.
Talos himself was a dragonborn. But that's before he became a divine. Akatosh was the divine that had the aspect of a dragon. It's said that Akatosh gave the gift of the dragonborn to Talos, and same to you.
But since Akatosh is chief among the divines, couldn't he also just order Talos to return to Mundus in the form of the Dragonborn?