I go to a top 5 organic chem university and am not ACS certified for my BS. I will say the opposite and say it doesn't matter at all if you are ACS certified. Or at least, it matters <5%. Very little. I was not at all concerned about not being ACS certified when I applied. It was never an issue. As long as you take a fairly standard undergraduate curriculum and show good research potential...
Yeah, sometimes I do. I picked my school 100% for my PI, and sometimes I think I should have considered the environment and the actual institution to a larger degree. I will not regret my decision in 5 years though because my school and my PI will put me where I want to be.