Preach on Kate!
I honestly don't think many culinary schools actually have admission standards, especially if you're not going to apply for the September class when all the high school students tend to want to start. My class at NECI, for example, only had twenty students. I think butts-in-seats was more important come admissions time than "most likely to succeed" was. That said, 1/6 of my class is already gone (kicked out, gave up, moved on), and we're not quite finished with the first semester! That, my friends, is intense.
So far as grades go, don't get worked up. What matters at cooking school is effort. If you'll put in the energy, somebody's going to get you through. It's a trade school. They're more than prepared to help you out if acedemics aren't where your talents lie. You just have to put in the time. The only difficulty I foresee in having poor marks, as I also did in high school, is in getting scholarships. The VFW, in my opinion, wouldn't know a stellar essay if it drafted their sons. When they say "merit based" they mean "did well in high school."
Best of luck,