Just a warning to anyone trying this, certain devices are seen as "composite" devices by the mac, and require the mac composite device driver.
The way that parallels works is by unloading the relevant USB drivers for your device and then "stealing" the USB device for itself. However, composite devices are not able to be unloaded.
The STAReBOOK is not a composite device, but for whatever reason one of my external keyboards is, and give some bizzare error that an application cannot release the USB device. If you do have a composite device loaded, the STAReBOOK will never get released from the mac to parallels, and so keeps erroring until the composite device is physically removed.
Otherwise, all still good on my STAReBOOK front