While the HS might not require math courses once a kid gets past a certain point, US colleges do not like to see the student take off a year (or more) from math. Someone might make a similar argument to stop taking foreign language after a year or two if the kid knows what he wants to study and foreign language is not needed. However, the decent colleges don't like to see this. It is a silly game, but we all need to learn to "play the game" to get what we want (and that extends well beyond HS).

As for the tutoring, middle kid's friend just recommended her for a position at a (paid) tutoring program where this friend works - I'm a little concerned since she could potentially be tutoring classmates or older (and I know I wouldn't want to pay and find some kid is tutoring my kid - but this is for another thread.)