Most of the APs available are on the required subjects. My DYS 14 year old DD (a sophomore in HS) is taking 3 APs (physics, chemistry, computer science) and one Post AP (multivariate calculus/linear equations). Two of those are required courses (chemistry and math). The other two count as elective credit.

I don't believe APs are any more difficult to a PG child than regular courses are to a ND child. My dd spends less on homework than her peers (approximately 2 hrs a day).