Hmm...a very thought-provoking post N3. I'm not sure if I believe that God would put a child through any test, whether of suffering or anything else.
For one thing, you just don't get that in the Bible. Abraham's great test was the sacrifice of Isaac - it wasn't Isaac's test, it was Abraham's (if you see the distinction). It's adults who are tested in scripture, people whose faith has already been 'tested' in the little things before moving on to the big guns.
Like, going back to Job, God already knew him to be a person of integrity, "blameless, upright, fearing God and turning away from evil" (Job 1 v.1). So I get the impression Job had already endured - and passed - lots of little tests, lots of temptations thwarted, lots of times when he'd remained faithful to God when it was tough - so what you get in the book of Job is an escalation of the stakes rather than a bombshell out of nowhere. This makes me think of a fantastic book I'm reading which had the little sentence in it that 'God calls us to die to ourselves many times daily' so that we can know his resurrection power.
Another OT exmple that comes to mind is David's comment re. Goliath - "The Lord who delivered me from the paw of the lion and from the paw of the bear, He will deliver me from the hand of this Philistine" (1 Samuel 17 v. 37). So that's the Biblical idea of God testing his people - testing faith in order to strengthen it by starting out with comparitively little things, then upping the ante as people rise to the challenge, not to make their lives unbereable but to show them how much they can achieve through faith in him and with him.
THe suffering of children is a much harder thing to understand IMO and I can only say we live in a fallen world and we are born inheriting that inherent fallenness, imperfection, broknenness of humanity, both physically and spiritually. Which is why so amny innocent children suffer, and die, through no fault of their own and dure to no sin and no test (how could God test a child? that would be so unjust).
The thing that gives me comfort and hope there is that Emmanuel - God with Us - CHrist is there with us in the midst of our pain and suffering, and on the cross he suffered more than anyone ever will so He knows and he goes through it with us. And I so believe that each little one who dies will be in heaven, being cherished by the heavenly father. That doesn't lessen our grief here on earth - I can't imagine anything worse than losing a child.
Sorry, another rambling, long post! I'm not offended at all by what you say, IMO it's good to question, to be honest with oureslves, to reach towards the truth.