Interesting memories from your ideas: Snap open, rearward sliding lower doors was the best system tried during some study done about 30-35 years ago. The doors had to be "open" above hip level when the rider pushed the thumb release lever. Test riders felt this would be dangerous in a simple low speed fall. At that time, the mechanism was spring loaded with a long lever to pull them shut.
Another problem found during testing, I was told, was rapid front tire wear under almost all riding conditions and very difficult brake control. I never got to see any of this stuff, but was contacted to discuss ABS methods for a possible sidecar type adaptation. The language difficulties made our discussions complicated, but I know the sidecar type design became a dead end. Keep in mind, this was all many years before the advent of modern VSC, multi-channel integrated ABS, and computer controlled electronic power steering systems.
Across the other ocean, Honda did some really good work on motorcycle design safety and found the best solution is to eject the rider cleanly with as little injury as possible during the actual impact/rider ejection event. The production result was the PC800, which you can still find good ones on the used market.
If you find one, you should fabricate a short handle, large Hex head tool to replace the O-rings on the sides of the cylinder heads. The fully enclosed engine tends to cook seals and O-rings on these bikes, which means you can often buy one cheap due to the oil leaks. That was how I got mine, many years ago. Don't have the bike, anymore, but still have the tool if you need to use it! Wonderful bike, by the way, and incredible gas mileage for something that can cruise so fast (but they eat front tires).
Physics is against you on this idea, and there has been some pretty big money spent to prove that fact.
JimL