There are so many things I would like to address about accessibility, and I will get round to it eventually, but in the meantime here’s a good roundup of the issues, and some good reference sites: Accessibility myths and misconceptions (456 Berea Street).
One of my favourite resources to better understand the issues (instead of focusing on scoring items off a checklist) is Skills For Access: the Comprehensive Guide to Creating Accessible Multimedia for E-Learning