Right, they call themselves 'People of the Root.' They're known as Argonians, their elven sobriquet, to the rest of the world.
And Saxhleel are what they are calling themselves. Or at least one of their tribes.
What limits are these? Is Mythopoeia limited from controversy?
Nope. It presents the controversy. Limits are the will of developers.
You assume the existence of evolution? Why did you conclude this?
Me? No, not me:
The men and the mer branches of the Ehlnofey further evolved over time into the sub-races. But do the beast races also share a common ancestor in the sense that all elves descend from Aldmer? Are beast races "sub-races" of an Aldmer equivalent in their evolutionary line?
The Khajiit are certainly speculated to have descended from Bosmer
But if you ask me, I think that evolution is present in TES. Both Bosmer and Altmer (and Chimer) are evolved from Aldmer, and they are distinct from them. Both Aldmer and Nedics (and Yokudans) are evolved from Ehlnofey, but they are all distinct.
But I suppose the evolution in TES is quite different from real-life evolution. Maybe it's the Aurbis or something else that influence on the evolution so it goes much faster.
But they were created by Hist.
No, we don't know exactly. They may be changed by the Hist from some original species.
Dragon Breaks are similar to what it was like during the Dawn Era, with non-linear time.
The Dawn Era was something [super]natural, when the Dragon Breaks are malfunction. They are not exactly the same.
It's the same reason why we get Akatosh, Auriel, and Alduin. All of them are the same god, but they are different. Akatosh is a preserver, and protects Mundus. Auriel seeks to escape from the prison created by Lorkhan, while Alduin seeks to end the kalpa.
First of all, Akatosh is Lorkhan (or Shezarr if you want). So preserver is Lorkhan, but not the other gods (Alduin the World-Eater, or Auriel). But I don't know why are you telling about it.
Basically, during the Dawn Era different groups experienced the same event, but their views caused them to see it differently.
But Khajiits didn't knew about the existance of mer other than Bosmer. So then they are talking about Bosmer it their myth, they mean "elves". And by "elves" they mean the progenitors of all elves, the Ehlnofey, from who other sentient races were descent.
No, he found out they are no longer mer. They still come from Aldmer.
From Ehlnofey you mean. Beastmen already were in Tamriel when Aldmeri came to it.
Please read about them: http://www.uesp.net/wiki/Lore:Ehlnofey