If I retook the test...

If your score tanked on the second try, they'd surely ask you about it, but if it goes down 20-30 points, they probably won't. The highest score is what matters. But don't worry about that. Just be well prepared!

I believe they take the most recent or the highest depending on the school. But the number of times you take and the number of times you cancel the score will be available to them as well.

I've taken it 3 times. I've been told by adcom people whom I have quizzed at info sessions, all for top 10 schools, that while they do have access to your scores, they take the most recent as the true measure of your ability. Some schools, for example Tuck, will even look at multiple tests and take your highest quant and highest verbal raw scores, from separate tests if need be. The only time they look askance at multiple takes is if you've broken the 700 barrier and then try for something even higher. In their eyes, that's a waste of time and shows that you don't really know what's important. Write crappy essays, and even a 770 won't help you. But really good essays coupled with a 700 or better, or frankly even a little lower than that, and you have an excellent shot.