Prioritizing Accessability

Since the discussion on Tuesday, when Kevin mentioned how accomodating everyone's needs ended up disasterously for a number of the students, I've been wondering to what extent accomodations should be made and in what order. For example, when he mentioned the lack of deadlines, I thought of an article I'd read some time ago on the Summerhill School. Controversial in its image as a school where lessons were optional, it nonetheless turned out high grades. Because of its loose guidelines, it feels like a complete counterpoint to their results. Of course, it's a school in service for nearly a hundred years rather than a one-off program - but how did they come to perfect it? On the other hand, what accomodations take precedence over others? I had a short-term injury that made it difficult to go to classes, but a friend has deathly allergies that make eating in the dining hall nigh impossible. While this is a very grand-scale example that hardly overlaps (as opposed to learning techniques, like fast-paced and slow-paced classes, visual versus audio learners, et cetera), when you're in a position when accomodating everyone starts to hold people back, how do you decide who to cater to? Does it depend on the severity of the condition, or of the number of people with a similar disability? Does a disability mean a person is fully disabled? How do we decide that, and how do we act upon that?