FW400 to FW800 backup + licencing query

[Whomper]

I have a late 2006 24" Intel iMac with 1xFW400 and 1xFW800 port, using SuperDuper! to back up to a G-Tech G-Drive Q 500Gb drive (USB2/SATA/FW400/FW800).

This works a charm - haven't had to use a backup in anger yet, but I feel a lot better for having it there. My wife has just got a new Macbook, and with ample space spare on the G-Tech I'm planning to back it up to a different partition of the same disk.

Queries:

1) Does the standard licence for SuperDuper! allow installation on multiple machines in the same household? I couldn't find anything saying yes or no on the website or in my confirmation e-mail.
2) If not, would it be feasible to connect the Macbook to the iMac via FW400 in target disk mode, then backup to the G-Tech over FW800, effectively a FW-to-FW copy? Would this be bootable?

Don't mean to seem cheap, but it would seem odd to pay for software twice to back up to the same drive.