Ahhhh la langue de l'amour. You're right you won't have much chance to use it unless you live close to Quebec or are stationed in 'gay Paree'. I would stick with it unless it keeps you from doing something more important like AP Calculus, AP Physics, AP Chem, or what have you. JMPO.
BTW DS's AROTC battalion did a field exercise in the taking and holding prisoners. He played the part of a Latin American guerilla. He was able to scream and curse in Spanish at all the MS 3's and 4's without recriminations.