I am a Duke alum and active alumni interviewer. I agree with prior posters about your ACT score being low, esp for engineering. I also agree that you should get your backups in order, as I’ve never seen someone with a 31 get into engineering (not to say it hasn’t been done, but it’s really tough). Your background is strong and you do have a chance, but I do think you have a much better chance of getting into some of the other schools. It would be a shame not to use your ROTC scholarship, it’s a tremendous accomplishment by itself. Best of luck to you.