For anyone else with the same problem as OP, holding Shift after startup (to disable extensions) worked for me.
More about the issue: when booting from the OS9Lives Universal 9.2.2 Install CD, my thrift store USB mouse (Lenovo) worked fine during the boot process. However, as soon as the system had fully loaded, any mouse movement would shoot the cursor to the far right side of the screen where it would refuse to move. I could still right-click and use the keyboard, but had to hard restart using the system power button.
It seems like this may be an incompatibility with USB Overdrive and newer (non-Mac) mice, because once I booted with extensions off (by holding Shift after startup) I was able to continue with my installation of OS 9.
What I'm up to: wiping the OS 10.4.11 system (with no Classic drivers) and installing OS 9 on a Quicksilver G4 that I found on the side of the road last week
looking forward to revisiting all the classic Mac games of my childhood! Thanks to all who make this possible here!