I have no standing or right to have any problem with how God set up the universe. If the Bible said that one out a thousand would be saved, then I would be "fine" with that. We all have a specific duty to take care of our children, God has no such duty to every person. Out of grace and mercy, He takes care of His elect.
You find nothing wrong with God placing his own children in a situation where they are tempted and, when they act on their temptation despite your warning, you cast them out of your home and let them fend for themselves; you not only punish them, but their offspring for all generations too!
Yes, Adam and Eve were punished for their sin. But, if you believe that they were still ultimately saved, as I do, then God could not have abandoned them forever, or else they could not have been saved. If I felt the need to blame someone for the sinful nature I had at birth, it would not be God, it would be Adam. Praise God that nevertheless, He has mercy on some.
If God created laws that govern billions of galaxies to move effortlessly and gracefully as island universes, He can integrate our decisions and weave whatever He wants with our free will in order to save those who are willing to be saved by choosing to come to Him.
I'll grant that God COULD do it that way, but I maintain that this would diminish His sovereignty and glory. With your puzzle analogy, we decide the shape of the pieces and then God has to make them fit. Of course He COULD, but that doesn't match your earlier statement that everything comes from God. If it did, then God would shape the pieces Himself.
So when God drowns His children because they turned wicked, we don't follow in His footsteps? I would venture to say that you would NEVER punish your children for their transgression as God punished His. Yet you would say that His is a just punishment and yours would be unjust, by necessity.
Yes, Adam and Eve were punished for their sin. But, if you believe that they were still ultimately saved, as I do, then God could not have abandoned them forever, or else they could not have been saved
We don't treat and punish our children as God did His. We don't kick out children out into the cold and let them fetch for themselves. We would call that child abuse in modern parlance.
With your puzzle analogy, we decide the shape of the pieces and then God has to make them fit
He gave us reason and freedom to make decisions. He knows the shape we will choose before we made it. But, just as you say that He allows evil but is not the author of it, you should be consistent and posit that He allows free will but does not make the choice for us, whether good or evil.