If I install Leopard on an Intel Mac 32 bit and make a SuperDuper! copy of it, will I be able to deploy that image to Intel and Power Macs and have it boot on both?
Will that image support 64 bit apps on x64 Intel Machines or G5 Power Macs?
SnapOverflow
Yes, you can build an image on an Intel machine and deploy it across any Intel or PPC machine that can support that particular version of the OS. By this I mean, if the machine ships with 10.6, depending on the machine, you'll have to install 10.6. Additionally, due to changes in the unibody MacBook Pros and iMacs, you might run into quirks, such as the machine always boots in verbose mode. You'll need to use Disk Utility rather than SuperDuper to create an image, as Disk Utility includes the "Scan for ASR (Apple System Restore)" utility which formats the image for quick, reliable push onto drives.
The most recent image I made was built on an iMac 20" (Early 2009). This image was 10.5.8 base. It worked on any Intel machine released at the same time as or before that model iMac and on any PowerMac G5 tower I applied it to.
I can't speak to the 64-bit question as I've not tested 64-bitness.
No - nor would you want to...
Whilst since 10.5.4 or so, Apple included all the necessary drivers for all products on the same architecture (PPC or Intel) so while an image can be used across the range you won't be able to use it across architectures.
The reason you wouldn't want to anyway is that many apps are Intel only hence regardless of OS X your image would be no good on the PPCs.
I don't really understand your 64bit question very few Mac apps make use of 64 bit - this is finally changing with SnoLo - and I don't recall any that work only on the Core 2 Duo Intel rather than the Core Duos. Your bigger problem is Intel only apps or the slight performance hit of a PPC app using Rosetta.