When it comes to the dual enrollment in math, did the counselor say he could NOT enter in the class desired or simply that they, "...want our students to be 16 and juniors."? Counselors will often attempt to dissuade students doing anything that isn't typical, however, unless there is policy against it, they also can't refuse enrollment if there isn't policy against it. I know we've been in the same situation numerous times and our assurance of knowledge of the risks and insistence of enrollment in particular classes have resulted in exactly that. If you're not comfortable with that approach, ask if your child can try the arrangement and if it isn't working out make changes at that time, assuring the counselor that you're aware that there are risks but that you feel it very important that the arrangement is attempted for the well being of your child.