(2) Inequality is mainly to exercise your thinking, which has something to do with the university, because you must still use inequality in advanced mathematics, but it won't be too deep.
(3) If you only think about college, there is actually a lot of time for you to study by yourself in college. But as far as mathematics is concerned, taking these elective courses is to exercise thinking and cultivate logical ability.
I hope my answer will help you. Work hard.