ST files are simple floppy disk images, which contain only sector datas in order. There is no info about floppy geometry, what may cause problems. I suggest you to try MSA images if possible - they hold disk geometry.
"I'm still waiting to hear back from petari about his PPDRIVER I bought, so I haven't actually tried it yet. Once I get the driver and set up the SD to boot as a hard drive, can regular .ST files be copied to the SD card and then loaded through CE_FDD? "
I'm on sending PM to you - but forum is damn slow again. There is some problem with e-mailing, as I posted SW in Wednesday.
Famous Schrodinger's cat hypothetical experiment says that cat is dead or alive until we open box and see condition of poor animal, which deserved better logic. Cat is always in some certain state - regardless from is observer able or not to see what the state is.