[dnanian]

To answer:

1) Yes.

2) It doesn't need to be scheduled from an Admin user, but it needs to be unlocked by an admin user. That user doesn't have to be logged in, they need only specify their name/password.

3) Well, remember they're Sparse Images. And if you want to restore the image, yes, connect directly, boot from your Tiger install DVD, then use Disk Utility (in the Installer menu) to mount (File > Open Image...) and restore the data.