Ok, a few things:
You can't do a redirection with sudo like that. This is how you can do it in one command. Of course you can always just log in as root with "sudo -i" or "su"
$ sudo echo OFF | sudo tee switch
Like I said, I really don't thing that the switcheroo will even work with the nVidia driver. So you might be stuck with whatever you're laptop gives you by default. However, doing "OFF" on the intel card *might* work and save you some power.
Finally, why is it that you think the backlit keyboard is affected by the gpu switching?