He has to have some inclination, having conversed with her for 15+ years. I can only imagine that he's dismissed her show criticisms in person many times, given that they meet for dinner every now and then.
Martin has to respond to all of this. I don't believe he said "Stannis is going to burn Shireen." More than likely he told them Shireen gets burned in TWOW and they added Stannis into things for drama.
I have to imagine there was some conversation about Shireen after season 2 when they left her out, along the lines of "oh, but you'll need her for the sacrifice scene!" I could easily see them deciding they wanted it to be Stannis who does it, and then spending the next few seasons laying their groundwork for that change, similar to how they apparently planned out their Sansa change years ago.
And with regard to Linda, yeah, I'm sure she's said some things in private, but I'm sure he's said things in private, too. I don't know if he knows how much she projects all of that into the public. I'm sure he has some idea, but maybe not the extent of it.
Yeah, he's gotta weigh in, agreed. I can't imagine he knew they were gonna so blatantly pass the buck to him in the post show interview. They were literally like "we dunno, ask GRRM." Kind of funny in that regard.
And IMO, it all but confirms that the pink letter serves as the catalyst for Selyse to burned at Castle Black and maybe that's how Stannis wins the Battle of Ice. Clears the weather and allows him to win.
Yeah, whatever their conversations were, I'm really not sure if he ever would have been ok with them going out immediately after the episode to use him as a shield. I'm sure he'd like to put out the sacrifice scene in a preview, like he has with other show spoilers, but it's probably too spoilery with regards to Jon, if it's happening in the aftermath of the Pink Letter at Castle Black.