My middle kid turned down D1 mid major swimming offers because he wanted to play water polo, swim, and study Mechanical Engineering, and that narrowed it down to a very small few schools, so he went D2 and got stacked scholarships in all three. I can tell you from having a daughter swimming D1, D2 and D3 offer a better life. As for the Air Force, I can tell you that the absolute best people I have ever worked with or for as far as competence and work ethic enlisted in the military and got their degrees later. My oldest would not have done well out of high school going straight to college, and now he's an honor student. I wish your son the best. He can't go wrong with any of those options.