edit: It's possible he was referring to Glass being much mightier because per square unit of weight it's actually much, much stronger than Ebony. The full suit of Glass is less than half the weight of the full suit of Ebony. Also, theoretically, heavier variations of Glass armor exist, which are Glass all the way through and not just some Glass on top of chain and cloth, which would theoretically be much stronger than Ebony or even rival Daedric, but this form of Glass armor doesn't seem to exist in the game world.
I alwys thought there ought to be daedra-infused glass armour. I mean, if ebony can be spirit-infused to create Daedric Armour, why not glass for light (or medium) Daedric Armour
If Dunmer are simply changed Altmer, then they must be able to live for hundreds of years, even the lower classes. An environment like that of Morrowind would take off about a hundred years, but even so three hundred years should easily be reached by a Dunmer.
The Altmer are positively obsessed about keeping stasis, including a long life, though. They rever Phynaster, a cultrue hro, as god, because he taught them to live longer through a different way of walking. The Dunmer dont have such a culture.
It's not that simple at all. Orcs are changed Aldmer and they have the shortest lifespans of all races considered people on Tamriel.
Actually, orcs are even changed Altmer, which of course only reinforces your point.