Questions About Catholicism, Please Read Description?

Well, I was adopted from my grandmother when I was 4 and a half, and my new family (I'm almost seventeen now) is Presbyterian. My Grandmother was Catholic, and I just thought of questions that I found contradictory: 1.)What purpose does confession serve, if Catholics believe that Jesus died on the cross for our sins. 2.) Exactly what significance does the Pope have?(Why do people treat him like a God, what exactly is he doing that's so great that he is given a god-like status?) And finally, an unrelated note: Why are people feeling threatened about evolution being taught, it doesn't necessarily disprove Jesus, for it only answers one of the five W Questions (Who,What,When,Where,Why), Specifically How. Since how is an explanation of the process itself, and is not connected to "What", or "Why", then why do people feel so insecure about their beliefs that they feel evolution is a threat?