1. Definitely don't take the GMAT again! A 750 will make you no more attractive to an admissions officer than a 730, all other things being equal. If you hadn't done well on one part or the other (e.g., if you only scored in the 70th percentile on the Verbal section), then I'd encourage you to take it again. But, you're already at the point where you can't help yourself more with a higher GMAT score.
2. You are correct to wonder about your age. (And, when I say "age," I really mean your amount of full-time work experience.) Those schools, especially Harvard, have been trending younger in terms of median age of their entering classes for the past several years. If you apply this fall, you'll be over 30 years old when you enter, putting you in the oldest 10% of the class. Among top-ten schools, Kellogg, Booth, and Columbia are three that haven't yet swung aggressively to the younger end of the spectrum.
Veritas Prep | GMAT Prep | MBA Admissions Consulting | Co-author, Your MBA Game Plan
Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
For a limited time, receive access to five Veritas Prep Computer Adaptive practice tests when you purchase a Veritas Prep GMAT book! Buy Now!
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.
Veritas Prep Reviews