Nice review! I only read the book but this insight into the movie was really interesting to read, and it sounds like a pretty good adaptation too. I mean, if it's being said in red, it has to be true.
Although, I gotta ask, if the swamp is designed to sink anyone overcome with sadness, shouldn't it be sinking Atreyu right now? I don't think the kid can get any sadder. I'm just going to assume he avoided the sinking parts.
AURYN protects him.