About that Archdemon prison, the Solasan temple in the Oasis has a "repulsive" aura outside the door that isn't present inside (I always have Cassandra in my party so she's the one mentioning it), maybe the Dwarves felt something similar.
Right? About the mage thing. I also wonder who it was that spoke to her in her dreams because I feel like it is likely to be one of the characters already in play ie: an Old God, an Evanuris, a Forgotten One, Forbidden One? Solas? Mythal? I don't buy that it was actually the ultimate creator being of all the things.
It's quite possible she never claimed the Maker spoke to her face to face, that's another Chantry deformation of what happened. WoT vol.2 text make it sound like she had visions about her destiny and had fade-dream trip. She actually preached the Maker was all around them so she probably considered her visions and the ability to walk in the fade in her dream as the Maker talking to her even if nothing did so.
Doesn't it seem like the red tree is covering up the sun?
And I just realized it has the wreath of fire with a sword so it can't be that old. Unless it's visus, which was originally an Alamarri symbol for the lady of the skies. But the sword indicates it's at least post Andraste.
"The story goes that the Lady of the Skies opened one eye so that the light from her gaze could lead her people safely from the Frostbacks".
Maybe some Alamarri lived there once, since Skyhold is in the Frostback Basin.
That eye is freaking everywhere: the Seekers, some random rocks on all the maps in DAI, the elven fresco, etc. It even show up in DAO. I suspect it is a hint, it link various things together, although right now outside of the Seekers and the Lady of the Skies it's hard to say what exactly (the Seekers love owls too, they are a few made of stone around Therinfal, the same found in Skyhold...).
We don't know the Seekers origin and going by the way they are turned into Seekers, it's not that far away from some of the stuff the Avvar do.