Hi,
most of these commands are shell built-ins, so it looks good (very restricted).
You could even remove bin/rm to prevent the user deleting files (if that's what you want
Further, you could use quota to prevent the user from filling up your hard disk or put the chroot environment on a separate partition...
Oh, and don't forget, if the user should have access to the network, you'll need to copy /etc/resolv.conf (or /etc/hosts) to the chroot.
hope this helps!
nukkel