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...and you're wrong about this one, too.
Watchmen simply does not work as a movie. I think that since you've read the book, you filled in a lot of blanks in your head. The movie was nothing but a series of vignettes from the book strung together, some of which worked better than others, but which didn't add up to more than the sum of their parts.
What's more, you're totally off-base about the new ending. First, you neglected to show how the new setup actually COPIES The Dark Knight in a way that totally doesn't work for this story. Second, the new ending doesn't really even make sense within the world of the story.