That's a bit of a tangent, don't you think? The dwemer belong in another topic.
Dwemer belong in every thread eventually. Like CHIM and Vivec. There is no escape.
Backtracking.
So anyways, dragons. I like dragons. Now let's filter through it all.
Paarthurnax and Odahviing speak to the Dragonborn as though he (pronoun used for convenience, alter as needed in your mind) is one of their own, and that ghost, having only encountered one Dragonborn in Hjalti, sees the same in you. Therefore, I think it is reasonable to say that Dragonborn are, at the base, dragons in human form (OLAAAAAAAAAAAAAAAAF!) and, as the Book of the Dragonborn says, it is not necessarily a state a person is born into, although they can.
So, step two. Was Ysrgamor Dragonborn? Possibly, and if he was then that means that he was a dragon, without breaking good sense in your encounters with his human-shaped shade in Sovngarde. Now for his name, is it a Shout, and therefore a true name of a dragon? Well, you notice that dragon name-Shouts are their main traits. That works for Dragons who are immortal and are created in a full state, like Odahviing and Paarthurnax (Snow Hunter Wing, Ambition Overlord Cruelty). It may well be, in eras past, men who took on the traits of dragons before the full Pact of the Dragonborn happened may have been granted trait-name Shouts.
So dissect his name, I guess. SUMMAT BATTLE SUMMAT. "Morah" is focus, and I don't know if they clip words to make rotmoraag.