Schools will not see that you took the test and canceled it. Most business schools* don't care if you take it multiple times and will only look at the highest score, so it's not absolutely necessary to cancel if you get a lower score - but, since you already canceled, there's no point in paying to reinstate it.
*Note: this is not necessarily true of Ph.D. and other business-related programs. I'm only talking MBA programs here.
Next, whether a 710 is good enough...I don't know.
My area of expertise is the test itself, not admissions. We've got a folder here called Ask An Admissions Consultant, and I'd recommend asking there. Warning: they will want to know a whole lot more than just your score + "top 15 schools." The score is one part of an entire package, and the schools don't consider each piece separately. A 710 is a very good score, but if you have a weakness elsewhere in your package, then it's possible that you'd be advised to offset that weakness by going for a higher GMAT score. On the other hand, the rest of your package may be sufficiently strong that lifting your GMAT further isn't likely to have a big impact. So, when you post, let them know about your profile. (I'd also suggest letting them know the specific schools that are of interest to you. There's a big difference between the #1 school and the #15 school.)