I agree that artistically it's doable, and not simply just by pooling together all of Disney's well-themed coasters (though it proves a good point). I think it's artistically feasible to create
extreme thrill rides, like those at Cedar Point or Great Adventure, done with wholly immersive theming. European parks like Alton Towers, Phantasialand and Europa Park show glimpses of this approach. Some coaster types might lend themselves better to this tactic - doing Maverick with Big Thunder level landscaping would be a lot easier than building several mountains around Millennium Force. And ideally the park would be enjoyable for non-riders too, with a decent balance of other activities (including quality dining and relaxing non-thrill rides) to create a full experience.
Logistics is a big question. You address coaster capacity, and I'm not sure if the Cedar Point model answers that for you or not. My big question is the park's audience. There's maybe not huge overlap between theming fanatics (us) and thrill seekers (though I know a few on these boards
). I've known coaster enthusiasts who claim visuals don't matter
at all on a coaster, asserting nonsense like "Nemesis would be just as good in a parking lot." Or could an immersively themed thrill park discover a new potential guest who isn't served by the Disney/Six Flags dichotomy? I'm not sure at all...but I'm thinking this could be a fun freelance project to tackle.