Probably a better forum for this question.
I could understand where you are coming from - we always seek challenge and sounds like the business that's doing great has been around for 5-10 years and is getting old.
I think the MBA experience could give you the time to do some soul searching and explore a few career paths (with a legit excuse to sample them and not appear that you are not sure). I am not sure that you want to tell the adcoms this though.
I think it may worth a try - a WL at booth or kellogg is a worthwhile result, esp in 2010. I think this year should be easier (fewer applicants) though it has not been yet (R2 or R3 may be).
I doubt you need to get any better GMAT. 710 is plenty - would not waste your time.
You may want to schedule a few sessions with admissions consultants and see what they suggest and how they would rank your chances. The GPA is a downer of course but you can justify it by showing that you put time into your business instead.
I think it is very doable if you have the passion and energy - doable but not easy (never easy for anyone really so don't feel too special)
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