Hi! Thank you for the interesting analysis. I'm just chipping in to say that I'm anyother person who went from manga to superhero comics. Reading them felt completely natural to me after manga, though - which is possibly because I've only read a few of them, and those've been the really good ones (Sandman is what I started with).
And I still get confounded by manga speech bubble sequence sometimes, even in my tenth year of reading it. (Doesn't stop me from loving manga, of course!)