There's a bit of a problem with your technology theory. Technological development isn't a line, it's a twisting, branching thing that leads you to a thousand different things before you get to what you want. If they got to the point where they were making super ice swords and advanced camo gear then they would have civilizations so advanced that they never would have actually lost any of their wars. Magic just makes more sense in this case.
Now the valyrians, they could be science (if we discount the semi-historical accounts of them actually using magic as well as the examples in the show/books). Valyrian steel? A chemical in dragonfire alters it. Glass candles? Requires an energy current to light up. I mean, we know that these are magic but they could actually be explained away as science. White walkers? Not so much.
Also your explanation relies on psychic trees and ignores the inability of different species to interbreed so it already uses magic. We started off with warcraft levels of biological sense.
So a Targaryan rode her dragon south across Sothoros for years and did not find its southern end. Even halfing that trip accounting for return trip Sothoros is crazy big in area of land mass. Why wouldn't the lands of always winter follow suit. Also I'm 99% sure grrm has said that Os is a globe, so theres definitely wrap around. Also like you mentioned, the azor ahai/long night mythos extends over to far eastern Essos, where the five forts are... Which are by far the most interesting feature in the world imo given their size, construction and mysterious purpose. I dont claim to have any answers. Another thing to recall is that this wont be a typical good v. evil tolkien tale, and we have a bittersweet ending to look forward to(if ever penned)
So how did finding out that the COTF created the white walkers change your theory? It does keep up with the fact that they are humans, therefore dangerous. Do you think it will be the same in the books?
Sir your video is good I like to point few facts for you in the new encyclopedia of Ice and Fire there was Warg King it reads that he lived after the "War of Dawn" rule the area name Sea Dragon Point. That is where Starks got their Warg's abilities from please check it out awoiaf.westeros.org/index.php/Warg_King
A different level of intelligence in this video and very well done. I’m thinking if you combine the last portion about the Lord Commander and his love, combine it with Secrets of the Citadel’s History or Future and Smokescreens most recent video 5 days ago about where this will end and how... you’ve got the whole picture. Chills