Very interesting article on Stan Lee, I agree with you on Lee's role in creating an older audience for comic books, sure Marvel tackled some more «adult» themes towards the late 60s but its pretty tame compare to what EC had done earlier. In the documentary «Stan Lee's Mutants, Monsters and Marvels» he claims that he was the one who came up with basically the whole Norse mythology for the Thor comics.
At times he can be hard to take seriously as he walks a line between carnival barker conman and sweet grandpa, so I apply a grain of salt to much of his statements (a lot of salt in some cases).
Excellent list of recommendations, a lot of interesting stuff there. I'm really keen on checking out his horror work, especially Creepy presents Steve Ditko. I have a collection of early Dr. Strange stories by him I haven't read yet, maybe its time to dive into that.