Why does God have to stop a natural disaster from occuring? Why is it that if he allows one to happen that all of a sudden he's hateful and doesn't give a shit about anybody? People who say that God allows things to happen so that people will build their faith is ridiculous; people who try to avoid the discussion altogether with, "We should be happy for every bit of life we get," is being disrespectful to the victims of the disaster. Put that person in the middle of Haiti right before the earthquake and see how grateful they would be. I don't believe posessing the ability to prevent a looming disaster dictates its use.
leo, you said, "Both depict an innocent mortal being screwed around by Them Upstairs, but in RAH's version it turns out that it's the Devil who is testing him," which implies that God was testing Job. In the Biblical account, it was the Devil who tested Job. God allowed him to, but God did not do it. According to the Bible, Satan had gone all through the earth and went to God mocking him, saying that he could make everyone in the world turn their backs on God...that the only reason anybody followed him was because he protected them from things...a hedgewall of sorts. So God said, "Well hey you should see my servant, Job. He would never turn his back on me, no matter what you do." So Satan asks permission to try, which God grants. God did not initiate any of Job's sufferings. He granted the permission, which a lot of people would say proves that he didnt' care about Job. The point of the story isn't so much about Job as it is about Christians in general: people who truly follow Christ will always follow Christ, regardless of the circumstances. This is very applicable to anyone who wonders whether someone is a true Christian. People who curse God when bad things happen are not true Christians. Not preventing a disaster is not the same thing as causing it.