Actually I think we have no way of knowing if the Arlathan elves really did worship the creators as the Dalish maintain. What may have been passed down was a number of folk lore stories which the Dalish have interpreted as reflecting "true" beliefs. One thing that strikes me as odd is that if the lifestyle of the Dalish reflects that of the ancient elves, why did the latter live in cities and, may be, even underground? Why did the Dalish establish the city of Halamshiral? Was it because they were trying to mimic an idea of the ancients that they really knew very little about? I know that have to be nomadic by necessity but I just feel that something doesn't add up. Take burial customs. The Dalish bury them in the earth and plant a tree but the ancient elves were buried in stone tombs, so their modern practise does not reflect the ancient one. As Felassen points out, it would really be more practical to burn the bodies, like humans do, so spirits can't inhabit them, so I do wonder sometimes if the Dalish customs evolved out of a desire to be totally different to the humans rather than actually a reflection of the ancient elves.
That is why meeting a revived ancient elf, if it were possible, would be so fascinating because their true beliefs might be at variance with what the Dalish teach. Just look at Corypheus. Whilst some of what he said appeared to bear our what the Chantry teach, other aspects did not. And the fact that an Ancient Magister survived both their ill considered journey to the Fade but also the events of the First Blight, gave pause for thought to not just about the Chantry but also about the Grey Warden legend. Did the archdemon Dumat really lead the darkspawn? If so, where did Corypheus fit in? You see meeting him didn't really resolve anything, only raise more questions.
That is why I have high hopes of our foray into the deeper Dales because before it became the Dales it was part of ancient Elvhenan. There are going to be ruins and may be a chance to find some things out and raise new questions. The other thing is that even if Solas isn't an ancient elf himself, he may be able to commune with their spirits in the Fade and so acquire knowledge that way.
I have a weird theory that the reason (some) ancient elves were immortal was because of binding spirits to them. It would also partly explain uthenera--eventually the spirit needs to go home to the Fade to recharge, and now your soul and the spirit are inextricably bound.
As for the tombs... ancient elven tombs were meant for sleepers, not the dead (apparently). Though, I highly suspect as I've said before that only the nobility were immortal. Common riffraff very likely were burnt or buried like human dead, and they were most likely not immortal.
Retour en haut
..." But then I went there and sure enough they are wanting to move to a new thread since their OP hasn't updated the thread in a very long time.... 
