Why did God create a universe that allows for human suffering? Perhaps because understanding and then overcoming evil is necessary to achieve the highest good.
Right. So instead of just creating humans who are capable of achieving the "highest good" on their own, which an omnipotent god would easily be able to do, he decided instead to condemn millions of innocent children to a life of torment and suffering.
Your God is a maniac, and you are morally bankrupt if you try to justify children suffering in the name of "the greater good".
Are you equally torn up about the millions of animals killed in terror every day to feed humanity or the plants ripped from the ground and consumed to feed those animals?
The natural world is full of evil and good. The fundamental difference between humans and those animals is that we alone have knowledge of good and evil.
With this knowledge comes the power to transform it. To rectify and redeem the evil in ourselves and in so doing become something more then a hyper intelligent animal.
The world is not a permanent playpen for our coddling and amusement. It is a reality that calls to us and demands we grow into something better then what we are.