Would however explain why there are so many floating rocks with bizarre architecture and buildings on them, littering the Raw Fade?
It's possible, but my understanding was that these rocks aren't real. They are manifestations of the Raw Fade. There is a codex in HLtA that explains why the rocks float, or at least one theory on why they float. The theory is that rocks are naturally occurring, and unshaped by the hands of mortals. So the Fade doesn't know how to represent them accurately.
It was also my understanding that the only real thing in the Fade is the Black City.
But it's possible that real rocks were sent there during the Fall, just as it's possible the water seen in HLtA is from Crestwood.
They might be the result of buildings being pulled into the Fade when the Veil fell, constructs that collapsed into themselves when the magic maintaining them deteriorated, or fade-generated manifestations of old memories dating from that time, long since rendered unrecognisable as no-one alive (save Ancient Elves in Uthenera) can recall seeing them so the memories have faded (pardon the expression) with the passage of time.
Maybe. But as it relates to human history, Vivienne implies that there is nothing about a time when the Veil did not exist. All I have ever seen is human historical accounts of the Golden City. That doesn't mean some lost human accounts of floating cities in the Real don't exist somewhere, but for now we have nothing about it.
But why would Bioware introduce the idea that Solas created the Veil, when disproving this would suggest the Maker does indeed exists, something they have stated numerous times that they don't want to do?
Proving that Solas didn't create the Veil doesn't prove the Maker exists, it just puts us back where we were, with the mere belief that the Maker created the Veil. I think BioWare has introduced this idea in order to lead up to a plot twist and provide Solas a plot in which he fails because he is proven wrong, again. He is a villain now, and he has to be defeated. Having his plan fail because he was operating on faulty knowledge is a good way to have the next protag or the (ex)Inquisitor defeat him.
It could also present a conflict of faith among Andrastians. If Solas created the Veil, it disproves their faith. So they have their faith tested in this. Then they discover that Solas didn't actually create the Veil like he thought, and then the Andrastians breathe a sigh of relief because their faith wasn't proven wrong. That doesn't automatically make them right, it just means they weren't proven wrong.
Solas being the creator of the Veil fits with both the abilities shown by his Orb and the Anchor, the highly complex equations that we find in Trespasser that demonstrate the necessary technical know-how, coupled with his extensive knowledge of the Fade.
His orb and the mark have only been shown to manipulate the Veil, not create it. I don't know what equations you're referring to. I know there are some in the Vir Dirthara that Vivienne and Dorian can comment on, but I don't remember those equations being linked to the Veil in any way. Even if they are, that doesn't mean it's a guide to creating the Veil. There are also some diagrams at the Darvaarad, probably drawn by a saarebas that show the inner workings of the eluvians.
As for his extensive knowledge of the Fade, that doesn't matter. He has lived a long time and has dreamt for thousands of years. Of course he will know more than most. Doesn't prove he created the Veil.
Who also happens to be a powerful Ancient Elf, who was either a member of - or on the same level - as the Evanuris and once owned a fortress purposefully designed for "something big" according to Mason Gatsi, that happens have a name meaning "The place where the Sky was held back".
Powerful ancient elf, yes, but I doubt he was powerful enough to cast a magical vibration across all existence. Was he on the level of the evanuris? Not necessarily. It can't be confirmed at this point. Owning a fortress means nothing. It being the location of a magic event means nothing. The magic event itself is implied to be where Solas used his power to cast his spell. What that spell entailed is what is up for debate. I'm sure he did something that cut the elvhen kingdoms off from the Fade, but I think he merely manipulated the existing Veil to close in on gaps that existed since before Solas was conceived. It's possible that he created a magic that mimics the Veil, and this magic filled the gaps, but I think there is just too much evidence suggesting that there was a Veil before the Fall.
While it's possible that he might have been lying, there's a lot of evidence backing up or at least making his claim seem extremely plausible.
I doubt he was lying. I don't see a reason why he would lie. I don't see how it benefits him. I think he genuinely thinks he created the Veil because he had never gone outside of the elvhen kingdoms to where the Veil existed. So he discovers a type of magical vibration that repels the "Beyond", and arrogantly thinks he created a new form of magic. Just as I'm sure Sylaise combined certain elements together with high temperatures to start a fire and thought herself the creator of fire.
Besides, is it really so strange that a religion started by a human wouldn't ascribe something important to someone other than their god?
No, but the point is that the religion would be false in that case. Andraste said the Maker created the Fade, then created the Real from energies from the Fade and made the Veil to separate the two. If that is proven false, then it makes Andraste a fraud, and the story of the Maker a lie.
As Mother Giselle notes, some things may have been misheard or misinterpreted. She also points out that for various political and ideological reasons, the Chant has had various alterations made to the text, such as entire Canticles being stricken from it. So while it might have gotten some details correct, as a pseudo-historical record that's been edited more times than a wiki page, it cannot be held up as entirely reliable.
Right, but again, I'm not referring to unimportant things like how demons first formed. I mean the core beliefs. The Maker exists and did specific stuff, the Maker cursed the Magisters Sidereal when they brought sin to Heaven, the Maker spoke to Andraste, having strong faith will get you through the Fade and to the Maker's side when you die, etc.
The theory on how to get the Maker to return is obviously wishful thinking. Andraste gave no answer for this, as the Maker didn't turn away from mortals until she was murdered. So yeah, stuff like that could be all wrong and it would make no difference, but the important stuff has to be possible at least in order for the Chant to be something worth believing.
Speaking of Elves, is it just me or is Cassandra a little bit racist and xenophobic when it comes to Elven beliefs?
Why wouldn't she be? They're false gods, like the old gods of Tevinter. She is in favor of the truth, which is what's important. In Jaws of Hakkon she appreciates the fact that Ameridan believed in the Maker and the elvhen pantheon. She may not have agreed with him, but she believed the truth about his beliefs should not be suppressed.