Thanks, Calvin.
The choice of Jonah is an interesting one if your thesis is that the prophets show God's judgment. The sailors do fear God, but the primary message of the book is that the Ninevehites are forgiven when they repent and that Jonah is cared for by God even when he sulks. God doesn't punish in this book.
What does Ecclesiastes actually say about what humans can learn from experience? You've given some information about the book but I don't see how it fits with the claim you make. Apart from these individual passages in the book, can you say more about the "big take away" of Ecclesiastes? What does it say about God and our ability to understand God's activities in the world?