Agree with just about everything but this really. Not that DKR shouldn't/couldn't have it's own stand alone movie, but what this movie is supposed to be. I don't see it as a "Superman flick" so much as it is for a launching pad for the DCU.
It is a Superman flick though. It's the Superman sequel to Man of Steel.
In DKR Superman is a supporting character who's role is to further the story of Bruce Wayne/Batman........instead Snyder is using that side plotline, to drive a whole movie while mining other aspects of the classic DKR, to bolster Snyder's flick.
Honestly, the weakest part of DKR imo is the Superman portion of the story line where he's basically a one dimensional boy scout that does the bidding of Reagan without question really(which thankfully doesn't seem to be the direction the DCU is taking with Supes).
Agree to disagree on that being a "weak point" of DKR....Superman's role in DKR is perfectly effective given what he's meant to represent. Miller never wrote Superman to be a fully flushed out character worthy of carrying a movie.....he was a plot device. Giving him more depth to the point of it being a worthy of it's own spinoff for writers/directors would have completely defeat the his purpose in the story.
Again that's why it's a shame they're mining such a classic piece of material to support a Superman story.......they're stripping the source material of all virtually all it's mythologizing, symbology, and heart......to be able to show what Snyder thinks is the "cool" aspects of the story (The actual Batman vs Superman fight, Batman in the mechanized batsuit, etc etc)......it'll be a completely bastardized version of the DKR, that likely gets in the way of anyone telling the proper story.
I think the 'Alien Menace' angle is a lot more believable and interesting a plot device to pit Batman Vs Big Blue against each other without bogging down into the "mutants" side of the story line (which I honestly don't think would adapt overly well to screen).
The Alien story arc is perfectly fine for a story about Superman and Batman.....it just doesn't need to have anything to do with DKR. As for the Mutants not carrying over, it works perfectly fine when updated for a modern audience. It's basically what The Dark Knight Rises was, with Bane playing the role of the mutant leader. I wouldn't use it for a Superman sequel though, which again, is why I think it's a shame they're mining a classic Batman tale, to tell a Superman story.
If this is well written, it should do a good job of capturing that Batman character, a better Superman character than what Miller had, and provide a more believable/enjoyable platform for their conflict.
Good writing, would allow them to tell a proper Batman/Superman story without having to butcher the greatest Batman story ever told......it's not like there aren't plenty of other Batman/Superman stories out there to mine for material, either.