You ask great questions and are respectful for an Atheist.<quoted text>
If God knows what you will do, can you do otherwise? If so, then God was wrong. God can't "give" you a choice if what you will ultimately do is predestined.
I think Abrahamic religions all agree that God is outside of space and time. Our reality of hours, days and yrs are for us only. God invented them, and He is not bound by em. The Catholic Church teaches that God's ways are a mystery and we simply cannot grasp the wonder.
When He created this all, it was in one swoop. So yes, He knows all. Hitler was born and God knew what this man would do. But God didn't hold back His Spirit and allowed Hitler and only Hitler to make the choice himself.
Either way, its still free will on Hitlers part.