More generally, I've found that many tv season sets on dvd/bluray have very little to no replay value. Especially tv shows with numerous seasons released on dvd. Unless there's a particular episode I really liked watching repeatedly, most of my dvd tv seasons sets were only watched once or twice.
DVDs are just about filling up Bookshelves. They look great and inspire envy and jealousy in your friends.
Probably. There's a lot of subtle detail in the "Machine's-eye view" stuff, and a lot of the arc/mythology hints in various episodes might be worth seeing again once you know what it all means and how it fits together, so you can see it in a new light. As for myself, I'll probably want to revisit it someday just so I can see it in widescreen, since I still have an old TV and the sides are cut off for me.
There was another show that you had left off of the canceled list, Who Do You Think You Are on NBC (though I guess technically it was canceled quite a long time ago, but now is when the new season would be airing), but there's no need to add it now as it has arisen from the dead: TLC Brings NBC's 'Who Do You Think You Are?' Back From the Grave I enjoyed the show, so I think this is great news!