What is the chance to get into UChicago, Cornell and Dartmouth? what is the best fit ED school? [MA resident, 3.72 GPA, 1540 SAT, bioengineering]

Really appreciate the information you collected! It seems my son must take less 12 credit to be eligible for first year application. To be safe take less than 3 courses. He was thinking to take more courses but not report on the transcript for curiosity and maintaining academic momentum during gap year. Whether is it a potential problem?