Sorry to crush your hopes, but... What are you going to do with the faceplate? Put it on ebay to try and recoup a bit of cash? Well whoever ends up with the deck is going to check ebay and see if they can get a faceplate for it and have a nice stereo for about 30 bucks.
Seems you have covered pretty much everything you can do to keep you stuff safe. Only things you haven't done or mentioned is the car alarm, tinted windows, and an unorthodox install. Car alarm with backup battery will limit their time at your car, tinted windows will make it less visible, and unorthodox installation makes it harder to remove.
When installing the head unit, not only do you use a backstrap(unfortunately, no one backstraps anymore) Use different hardware to mount it, phillips, security torx. Speakers and amps should be mounted through bolted with double nuts, if possible, and with different fasteners. After you are done, go back and analyze if it would be easy to take if you just smashed stuff. Lot's of time installers will think something is secure because they put 20 screws into a thin plastic bracket. They will just rip out the whole bracket. Unfortunately, making is difficult for thieves means they will destroy you stuff in retaliation before they give up.
