I found calc to be very hard. So hard in fact that I think I failed that worse than I've ever failed anything in my life.
I didn't really see any similarities between pre-calc and calculus. My pre-calc was really a bunch of trig, but that might be just my class as different text books can have different stuff in them.
I haven't had any teachers that openly mean about their grading policies. Here's a website you should check out before signing up for classes.
http://www.ratemyprofessors.com