On the topic of the Comics Code: wasn't the Dark Age at least partly the result of a backlash against the Code-censored Silver Age? It's sort of like how the excesses of the '60s were a backlash against everything that the '50s stood for. Preventing the Code from arising, and allowing horror, crime, and similar comics to survive, means that you won't see comics being censored and sanitized to the point where they're pigeonholed as being just for kids. In turn, you won't see the backlash against this censorship that led to everybody jumping onto the "darker and edgier" bandwagon simply as a means of giving the big "fuck you" to the Code and the Silver Age.
Any thoughts as to how the comics landscape would look without the Code? Personally, I think that superhero comics would make up a much smaller chunk of the market than in OTL. The Code really helped save superhero comics, as after World War II, they no longer had the Germans and the Japanese to fight. Other genres started growing: horror, crime, romance, humor, etc. A lot of these wound up getting gutted by the Comics Code, leaving only a few holdouts like EC (which only survived because of Mad Magazine) and Archie. Without the Code, I don't think we'd see anything like the ages of comics that we'd see in OTL. There would be a lot more variety, and a greater deal of public acceptance due to the fact that you don't have the censorship or the dominance by action-packed superhero comics. They might wind up occupying a place similar to manga in OTL Japan -- with some level of mainstream acceptance as an artistic medium (although not as much as TV or film), rather than the perception that it's lowest-common-denominator trash made only for kids and basement-dwelling nerds. You might even see greater acceptance of animation in general as art, rather than having the "animation age ghetto" limiting it to just kids. Hey, a man can dream, can he?