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2nd - "I saw a picture of notes where GRRM denied that Coldhands was/is Benjen. It was just handy for the show.":
There is the theory that Bran is actually Coldhands, as well. Bran had a vision of Coldhands being created and part of him got "stuck" inside of Coldhands.
The Children of the Forrest thought that Bran saw the vision of them creating the first white walkers but in fact he saw the vision of the Children creating Coldhands so this one could lead and control the white walkers, which already existed at the time and got out of control.
Theories are everywhere.
As far as I recall, he had no such vision in the books, so I would not base any theories on this one.
3rd - "Why should Syrio be a faceless man and why should he wear the mask of Ned? Also Ned would need to dead for a faceless man to wear his mask. They dont take faces from the living. Not to mention that they are both quite dead....":
Actually, Jaqen H'ghar and Arya proved this to be wrong when he wears her face in the House of Black and White, although she was alive.
Again, this only happens in the show. In the books, the "Kindly Old Man", whom Arya meets in the House of Black and White denies even knowing someone of the name Jaqen H'ghar, nevertheless taking his physical form. And it is quite clear that they skin dead people for the faces they wear. And also, there is an incontinuity in the show as well, as we see Arya in Season 7 having different skins that she can put on, that would confirm the mechanics of their illusion. Even though the more experienced faceless men can quickly change their looks, they definitely need the masks. Also, in the books, Pate in Oldtown dies in the Prologue, then somebody with a matching appearance shows up later on... Heavily suggesting that you have to be dead to be turned into a face for the faceless men. Again, the showrunners ruined everything and got fans rather confused in my opinion with their carelessness.
"Also, JRRM is usually not working any magic for super surprising turns of events.":
If GRRM doesn't use any magic, how does Beric Dondarrion resurrects? How does Lady Stoneheart exist?
Also, I don't care what GRRM writes in the 6th book. The show is way ahead of the books and following its own path. It may use events more dramatically than in the books. For instance, some characters that are already dead in the show (Cersei blowing up the Sept), are still alive in the books.
I think ElPopelos did not phrase it perfectly what he was trying to say. I think he only meant the MAJOR turning events, like Bran's fall, Ned's exeecution, the Red Wedding, the Purple Wedding (Joffrey and Margaery), Cersei going to prison, etc. Yes, there is magic, yes, there is some magic in big turning points (Dany's dragons being hatched, Renly being murdered, Catelyn's resurrection) but nothing that is not at least foreshadowed. Bringing Catelyn Stark back from the dead was way after the Red God's resurrection was explained. And also Arya had a "dream" (basically warging into Nymeria) where Nymeria finds the body of Catelyn, so it was all hinted at. But Ned's execution was way before the Faceless Men ever made an appearance in the books/show, so it would really be out of GRRM's style to solve it that way. And also, everyone was kind of expecting King Jojo to let Ned go to the Wall, even Cersei gave him this advised, and even she was surprised at Joffrey's decision. So if nobody expected him to die... why would they swap him?
And a personal note, Off topic in the Off topic section: I really think Syrio indeed was a faceless men, mostly because of the phrases he uses when speaking with Arya. They hint at it at least, but you know, we will probably never know it for sure. But if you really think about it, it feels like Arya was kind of targeted by the Faceless Men if we count Syrio as a FM. I mean... why would a FM try and go to the Wall with Yoren and Co., then, when set free, not proceed towards the Wall, but going the same way Arya does? The Faceless Men have missions, and they do everything to complete their tasks. They are skilled killers, so if Jaqen indeed had to go to the Wall, he would have ended up at the Wall. Instead, he surprisingly went the same way Arya did. I know he kinda felt like he owed the 3 lives to the God of Death because Arya took them from him, but still... they only move when they have a mission, they don't just wander around. So I really don't understand why he would take that journey. And eventually, based on the descriptions of some unnamed characters, leave the coin with Arya, then go to Oldtown... I mean, if he really had to go to Oldtown first, he would have gone straigth there, and not start travelling North... Rant over.