Re: Ignoring Superman 3 and 4
I think it was a mistake to ignore Superman 3 and 4 despite how poorly each movie was received. Including them wouldn't have detracted from the story Singer wanted to tell, perhaps could've provided more nods to be placed in SR (for fans of those films and I'm sure they are out there; I liked Superman 3 and didn't think Nuclear Man was that terrible an idea), and it would've cleared up confusion about where SR fits in the Donner-Singer continuity.
Personally I think that Singer should've just made SR a complete reboot, with some nice nods to the Donner films, Smallville, and other Superman lore. It made little sense to me to have a whole new cast and tie say they are the same characters from the 70s and 80s films. Routh did okay channeling Reeve but Bosworth didn't even try with Kidder. I thought Spacey took Hackman's reins very well, but I think he could've given an even better performance if he hadn't been shackled to the old films.