Wow, Cobra! What an incredible design! (Are you an architect or engineer in your other life?) You could market this coop!
I love all the access devices. I may steal your idea for the top-opening run, if you don't mind. My run has to be short (40") to keep it concealed behind a wood fence. I'm in the process of building it now, so it would be easy to simple add hinges to the "lid". What do you use to fasten yours down?