If I take more than the 11 or 12 classes that I need to fulfill the major requirements, can I decide not to count the classes I took Credit/D/Fail or received non-A grades in for purposes of distinction?

No. All courses in the major must be counted. If a student has taken more courses than are required for the completion of the major, then all of his or her courses must still be taken into account. A student may not be nominated on the basis of his or her 12 or 14 best grades; the performance in all courses taken in the major determines his or her eligibility.