You can't keep someone from accessing a system just by locking down the interface.

If you're worried about "security" LiteStep isn't a solution. You should use the filesystem perms, and other methods of securing access to the system.

If you want to present a defined user interface that provides access to a specific set of applications, then LiteStep is a great choice. Just don't assume LiteStep can (help) prevent access to the system components that the user has permisions for.

And no you can't override Ctrl+Alt+F1. A code modification is needed (as has been done).