2 bootable partitions in a laptop HD
 

I am new to Superduper (and making bootable HD copies etc) and trying to familiarize with the features. So I apologise if this has been covered before (tried to find it)
If I make a bootable clone of my Powerbook G4 HD (running 10.4.11 and classic) on one partition (journaled) and if I make another partition for Sandbox (journaled to make it bootable), will there not be a conflict for the laptop during start-up as it would try to start from both systems? Is that a bad idea?
I am trying to make bootable HD backup and then replace my internal-dying-hard drive with the new one and have the Sandbox in place so that I can avoid doing this again after the event (such as fatal errors accumulating in the HD).

No, it only tries to start up from the volume you've set as the startup volume. But, Sandbox won't help you if your hard drive dies -- that's what a full backup does.

I will be making 2 partitions on a new hard drive (connected externally via firwire), try to clone all the current internal HD (full backup) into one (start up) partition and if that works successfully, will make a sandbox of that clone on the second partition so that when I replace my corrupted HD with clone+sandbox containing HD, it would function and retain the sandbox option for future. Am I correct doing this way (for the laptop) or the sandbox should be ideally on a different external HD?
Thank you in advance for clarifying my queries.

You can do that, yes, but the Sandbox is going to be tied to the original source drive. If you start up from the Sandbox and the original drive isn't present, it's not going to work. The backup, of course, will be fine.

Thank you for quick replies. Very helpful.