Adam and Eve were created to be eternal beings. When they sinned they started aging although they still lived for centuries. So God was telling the truth by saving, "The day that you eat it you shall surely die." What was sure is that they would die. God wasn't saying that they would die that day.

No, God isn't evil. God is free to do whatever he wants with his creation. God has the right to have different rules for mankind than he does for himself.

God wasn't surprised by what Adam and Eve did. God is never surprised. God had taken into account when they would do.