Can you refresh my memory please? Did PW actually say he wasn't a dreamer? Only the description of what he does when is goes to sleep "where the veil is thin" sounds a lot like a dreamer. Or has he really discovered a third way of entering the Fade at will? The first being with lyrium, the second being with blood and the third doing what he does?
As for being mostly self-taught. Well of course he could have learnt something from an older apostate, which is why he knew how to stay clear of Templars. He could have learned from the Dalish or may be he learnt from the Spirits themselves. After all humans were meant to have learnt certain types of magic from demons. Solas can do things that other mages never thought of doing and we're assuming that means Rift mage because we've never had one of those before, so may be he did learn from a Spirit.
We've never really encountered a self taught mage before. Malcolm Hawke was in the Circle before he fled with Leandra. Hawke and Bethany were taught by him. Morrigan was taught by Flemeth. Most mages get hauled off to the Circle the moment they show any magical aptitude.
Might be worth asking what his family were doing in the village he came from. Elves, apart from the Dalish, are generally found in the cities and have to get special permits to move around from one part of the city to another and from city to city. When elves try to move away from the ghetto, it is very often their human neighbours who drive them back again. Was it in fact a village of apostates? There was a Mages Collective in Ferelden and quite possibly elsewhere as well. We had the mage underground in Kirkwall. It makes sense that in the past a group of mages might have got together for protection and just like in the Circles, distinctions of elf and human don't apply when you have a common enemy in the Templars. That could be why he doesn't like applying such distinctions. Did something bad happen to his village which caused him to go off on his own into the wild or did he just go walkabout and never went back?
There's going to be plenty to talk about with Solas beyond just the Fade.