To run PowerPC applications under Rosetta, you would need to be able to run the Intel versions of Mac OS X 10.6 Snow Leopard Server or Mac OS X 10.5 Leopard Server in a VM. For example, this would allow running ARM-based Linux variants, or macOS Big Sur in virtualisation on an Apple Silicon Mac. This will not extend to running older macOS versions (macOS Catalina 10.15 or earlier), since they are Intel operating systems.
When VMware Fusion is released for Apple Silicon Macs, the expectation is that it will initially allow virtualisation of ARM-based operating systems.
The short answer: no to scenario 1, and scenario 2 is not applicable or relevant.
