Reverse engineering is probably not the place to learn to code.
That being said, I don't think the $200 Chromebook is going to cut it. Eventually he's going to want to run a Windows VM.
As far as learning and reversing goes, it has often been helpful to see how something is working while also attempting to make it work for me.
Did you end up buying the Acer C720?
That will be the one I more than likely go with. I was worried about 2GB of RAM coming from a Windows background, 2GB isnt anything. But apparently it runs fine in Ubuntu.