Your profile is compelling enough for you to apply to the Harvard 2+2 program.
If you believe that you can score higher on the GMAT, without spending another few months studying, I would encourage you to retake the test. However, you really do not want to sacrifice time studying that you could spend constructing your essays. A 720 is competitive, but since you are from an overrepresented demographic, any additional points will help. Again, do not sacrifice time studying that you should be using to construct your essays.
Your lower undergraduate GPA needs to be placed in the proper context. It seems that you were very involved in many "leadership" type activities. I am impressed by your rather lengthy list of papers, internships and projects. This will add an extra dimension to your candidacy. Specifically, it will be slightly acceptable to have a lower GPA since you are so heavily involved in a number of other activities.
The most important thing to remember is to not concentrate so much on the technical nature of your accomplishments. You want to focus on leadership and how you interact with people. That is, how do you lead, what did you learn from it and how is it created the person you are today. Harvard is all about demonstrating introspective leadership. They know you are smart guy, but that is a huge difference from being a leader or effective motivator/manager.
Paul Lanzillotti | Founder| About | firstname.lastname@example.org | 877.866.9251
Schedule a Consultation | Twitter | Blog
Download "How To Apply" Guides | INSEAD | Columbia | Harvard | Wharton