I have many areas of interest, how can I study all of them?

The fact is that one cannot register for many classes outside of his major / minor. That was the main reason why my D. had 2 minors. As I mention, you can have several in combo of major(s) / minor(s), and then after taking all the classes that you are interested it, just drop them. This is the easiest solution to your dilemma and that has worked perfectly for my D. and others around her.