Executed the CLI commands succesfully...
USB flash drive still doesn't work.
I also installed AMICDFS (using the device of subwayusb.device - not sure if that would be correct) and the CD drive doesn't work either.
Posting the output of PsdErrorlog would surely help a lot to analyze the problem.
Do NOT use subwayusb.device for any mountlist. You usually don't need a mountlist, but if you do, the device is called usbscsi.device and no, it cannot be found in DEVS:.