I see your point. Here comes my but thought
... Aren't we suppose to treat the information sources in the game as "real"? In-game real I mean. If yes, then the "truth" as heard from Solas could also be diluted. Remember he is the great trickster or deceiver. What I'm getting at is, we can not simple dismiss the other sources of information as non-important. Solas can not and should not be the only source of information referring to the Dales. I refuse to accept this. Otherwise the tidbits of information littering the game here and there are nothing more than garbage in the game. I have come to understand the information in this game to be a type of puzzle. Just like the Dalish information is taken with a pinch of salt so should the information from Solas be treated as well.
I think we can try to go through it like a detective.
First, Solas supports the Inquisition right away, so we can assume, Cory's opening of the veil was not what Solas wanted. So he wanted Cory to do something. Cory however seemed strangely... dull for a "bad guy". It can be assumed, Cory wasn't really aware who Solas was, otherwise Corys outcry to Dumat to "help him" would not be there. But what DID Solas think Cory would do? I have the impression this is the weakest part of the story, because Solas just handing the Orb to Cory without any real instructions... could he not forsee that Corypheus would do exactly that? That sort of miscalculation either reveals an unexpected stupidity in Solas, or a weak part of the Plot from Bioware.
Second, we must assume Solas did not want to raise any suspicions. If one has to hide his true identity, we can guess he will agree with the Inquisitor. Reversly, we can thus assume where he critizises the actions of the Inquisitor, he is genuine. And in these we have the following:
- Solas heavily critizised me killing the Elven Priests in the Mythal temple, as a waste, destroying the remains, so he seems to like the old Elven world; there would be no profit in lying about that
- he intervened with Cole, trying to keep him more as Spirit, and critizised me a lot for helping Cole to become more human PLUS
- he told how he thought the Spirit World and the Mundane World should be connected, a VERY risky thing to say given how most people view the spirits and the spirit world. Again nothing truly to gain form saying that at this time, so we may conclude he is somehow honest here, in his support of Spirits. He does seem to see the seperation of material world and "Fade" as wrong.
Third, all tricksters are arrogant, believing in the supriority of their intellect, so they never can fully conceal their true nature and desire. He said, he failed. We can not be sure about what, but the connection of spirit and material world sounds like the most likely thing, he wanted to achieve. Morrigan muses, she too wants to see a return of the "magical ways of old", and detests humanity for seeing the Fade and the Spirits so evil. Solas repeatedly explains how the Spirits are mostly irritated and sort of "driven mad", when they enter the Material World, because it is not changable as they know it. So they follow their nature and try to change it otherwise, usually violent, but he claims, they are not inherintely evil.
ONE possible conclusion of the true origin of the Blight may thus be, that it is a result of the unnatural seperation of the Spiritual and the Mundane world. Without that strong seperation, there would be no "demons" and no Blight?
The big question is then: How did the seperation happen? I think that is the 1 million dollar question.