UChicago is definitely a reach, but no more a reach than Columbia university - they have the same range of acceptance rates (Columbia, 5.5%, U Chicago 6.2%). But, while I think that getting caught up with CWRU is not a good idea, I know that getting caught up with a college that has an acceptance rate of less than 10% as a dream school is a Really Bad Idea.
As I like saying to all the hard working high school freshmen and sophomores who come on here to ask about colleges - go back and Win at High School! You are already almost halfway there.