You are REQUIRED to send them AMCAS. Failure to do so is unethical and a larger problem then getting a poor grade or whatever as a HS student.
As a general rule, you should avoid taking ANY pre-med requirement at a CC. Certainly if you are actually attending a CC as a full time student for legitimate reasons taking some is inevitable, but even then, it's strongly advised to limit the number taken. If you have the option of avoiding CC classes, it behooves you to do so. Issues of quality and general perceptions of CC classes (justified or unjustified as they may be) make them undesirable for someone thinking of going to medical school.
Auditing of a CC class is okay, but who really has the time? Would a HS even allow you to do this?