Hey Jeff,
To your original question and as Jon mentioned, a 700 puts you in the club. With a 3.5+ in an engineering program and a 700, the adcoms won't be concerned with your academic ability. It isn't a differentiator, but it's definitely in play. Also, if you're looking to move to management consulting, it clears the cut off most firms place (a lot have GMAT score requirements kind of like in undergrad firms had GPA cut offs).
My main question for you is why are you looking to apply this year? You'll have 3 years at the time of application and that's a little on the low side when you're not coming from an "accelerated" career path (e.g. I Banking, PE, Consulting, etc.). So to your concern about leadership professionally and extracurricularly, I would say there IS something you can (and should) do about that.
Honestly, I think it may be in your best interest to hold off on applications for maybe a year or two. At work, actively seek out leadership experiences and see if you can line up a promotion. If that means switching companies, that can be an option. Outside of work, find something you're passionate about and use that as an opportunity to develop the skills you may or may not have the opportunity to develop at work.
Your recommendations can only help you so much - they will only be as good as what you can give them.
I don't mean the above negatively by any means - I think your goals and target programs (e.g. Duke) make sense. They're great programs and they'll really help you make that switch. However, a program like Duke is a very tight knit community and really looks at leadership (both professionally and other) to differentiate candidates.
I think you've got a little bit of time - so take that time to strengthen the rest of your profile and, if you have the time, retake the GMAT! A higher score is always a great thing and you have the time to focus on your development areas.
Cheers,
Bhavik