What should you do if you are falling for a friend and you want to know if she likes you but she is just so unpredictable and hard to understand should you leave it alone and not risk anything or what?

I think you should risk it. The worst that could happen is that you know she does/doesn't like you and your better off for it. I'd recommend the straight up approach, and just ask her to her face whether or not she likes you. Or you could wimp out and spend the rest of your life thinking back about what could have happened if you just got the guts to ask her out. Your decision.