In the first situation, why a Chromebook instead of, say, a tablet? Or an iPod Touch, even? Children don't tend to get the same sort of benefit from full "hard" keyboards that adults do, and there are devices cheaper than Chromebooks that can be similarly locked down.
> "Children don't tend to get the same sort of benefit from full "hard" keyboards that adults do"
How do you expect them to learn to, if you don't give them devices with keyboards? Sure, they could wait until that typing class in middle-school, but wouldn't it be better to have them pick it up themselves, much earlier?