Really a Perfect Plan?

Let me ask some even more fundamental questions:

• If sin is a fact in our world, and our world is a result of God's perfect plan, does that mean that God created sin?
• Or, put another way, what role does our free will play in the introduction of sin into our world. If God knew ahead of time that we would employ our free will to disobey, does that mean that we don't really have free will?
• Does the fact that an omniscient God would know ahead of time about our disobedience, does that make it any less an offense? If it does, then by extrapolating out to perfection does the offense go away?