I don't know whether this is different from the A3000, but on my A4000T I regularly switched off an external device while the Amiga was still running (obviously not during access to the device). I also have a Yamaha CDRW and it was in an external box for more than 2 years. Then I had an external SCSI HD that was formatted for MAC (Shapeshifter or Fusion, can't remember which) and lately formatted for FAT95 sharing between Amiga and PC. I have switched them all off at one time or another and no damage has been done to my Amiga. Same applies to switching them off while connected to the external connector of the CybSCSI device.
