Great job, although I have to say that I disagree with your assessment of DS9 challenging Roddenberry's philosophy. I think 'challenge' is the wrong word to use to describe what DS9 does; it doesn't really challenge Roddenberry's philosophy so much as examine his philosophy from a slightly different angle. DS9 still has every aspect of TOS and TNG's 'utopian future' present even in its later seasons, but what it does is examine those aspects from an outsider's point of view.
I do think that by doing that examination from the outside, it does show some of it's inherent weaknesses and therefore challenges that philosophy. I would consider it more in the vein of TOS than TNG. These are just some of the reasons we wanted to talk DS9; it is so rich with conversations about so many subjects.