I never understood why people get so hung up on the cannon. Play with or ignore it. I get that some players are familiar with it and could possibly contradict the DM's vision, but your the DM make it yours. Im lucky enough to DM for a couple of casual gamers who never cracked a source book or novel open. I also don't feel like there's a lot of homework involved with it. I have the 94 box set, skimmed the 3e core book, and gasped at 4e. High level NPCs? I see it as a way to keep PCs who want to destroy a town in check, and if I don't want them to be higher level they wont be. I like the Realms it what I started playing in and its the type of world I want to run my games in.