Thank you for your time in making the wonderful wiring diagram illustration. Keep up the good work.
Very good description of operations. Could you put a bulb in series with battery so if you make wrong connection ie positive to ground the light will be at full brightness.
You might find the following video helpful too:
Airbag Diagnostics | How to Simulate Airbag | How to Bypass Airbag
ua-cam.com/video/Pp-292wi4S8/v-deo.html