No one doubts that He knew what would happen, but He allows things to develop and uses unorthodox means to accomplish His plan (such as dying on the Cross, suffering in flesh, etc.). Looking at how this unfolds, He is not a Micromanager as you Protestants think of Him.
God teaches us only good. Whatever God created (read Genesis) was good.
Humans are authors of evil. Even when we do justice, we commit evil.
God cannot be the author of evil, because it is not something that glorifies Him. And His creation was done for His own glory, I think you'd agree. Otherwise, if evil also glorifies Him, God is both good and evil, and that would mean that He is not simple, indivisible, eternal and unchanging.
You guys are stuck on this omniscience and omnipotence trap, like the question "If God is all powerful, can He make a rock so heavy that even He cannot pick up?" That's not how God's omnipotence is. That's man's foolishness.
"Humans are authors of evil."
Well what about Lucifer/Satan? Is he a being created by God or a figure of man's imagination?