If God created all of us, and the universe....why did he make satan? i know satan WAS an angel...?

i also dont understand the adam and eve story. if God is the almighty and created everything, and knows how many hairs are atop each of our heads, and knows EVERYTHING, then he knew that eve would take a bite of the apple. o know, he gave us free will...and she chose to disobey God's request.was it so God and mankind would not be bored?it it were a PERFECT WORLD, i guess that would be kind of boring.....i think it would be nice. we just have to figure out what a "perfect world" is.