Hello eplaymaker, thanks for your question.
The GMAT question comes down to how assured you are of getting that 730. It could move the needle, indeed, but is it worth it to take that time away from your essay preparation? That’s a call you’ll have to make.
In terms of your career story, you do seem to have strong experience. Do you need business school? You’ll have to answer that question when you craft your career “story.”
The paucity of extracurriculars could be a challenge. Other than official volunteer activities, you may be able to mitigate the lack by speaking to how you engage with the world. If you can discuss your interests and passions and show the admissions committees how you take initiative, lead, and collaborate in those arenas, you could mitigate the lack of your formal experience in this arena.
I think you have strong experience, but if you cannot come up with some non-work examples to write about, I would say Stanford and Wharton are reaches.
Best of luck,
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