on on core. I earned four today (that is max, right) and I want to eat a popcorn ball with maple syrup. Is that fine?

yes it's just fine. Use your Ap's or your WPA for anything that isn't core. Great job earning 4 AP's!! oh and I believe there is no max on how many ap's you can earn, just like on flex, you just have to use them the day you earn them. HTH!