those 4 years are the years that you make your college basically.
Absolutely not, I never had a single class to do with computers in high school. I'm majoring in Computer Science right now, the Comp Sci classes I had so far I've done very good in. Everything besides math has no impact on High School. During my admissions he never even looked at my classes.
High School has such a little impact on your life, the only useful classes I've had were math clases. So choose whatever classes you would enjoy, or would be easy.