I am coming to the end of a military career. I have a Master's in IT and have MCSE and CISSP certifications. I...
have moved to upper management but still like to work hands on from time to time. I would like to teach, research, or work at the corporate mid-level in security. Should I train for more certifications or should I pursue more college-based work to remain viable for this career change?
If you want to teach at the community college level you're probably good to go, as you also are for the corporate mid-level in information security. If you want to teach at a four-year institution or something at the graduate level, you'll need to gear up and go for your PhD; the same thing goes for research work as well. For these latter kinds of positions, you really need a doctorate and should probably also pick something interesting and valuable for your dissertation topic as well.
Best of luck in your work or studies.