Except that I've already applied both BoingBag 1 and 2, as per someone's previous suggestion. Is there a way to undo those?
You can either:
a. Go to Devs: and rename "AmigaOS-ROMUpdate" (or whatever the file is called) to, e.g., "AmigaOS-ROMUpdate.off"
b. Edit your startup-sequence. Find the line with the SetPatch command and add the argument "NOROMUPDATE"
I recommend b. Ultimately, later, you'll want to narrow down which particular module is causing problems and skip that module while keeping the other ones. That's all done with SetPatch arguments, so it's good to keep the ROMUpdate file in Devs: as-is.