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Halfway decent comment so adding more:
The emergency descent altitude is almost always 10,000 feet. This is because most people will be able to breath without the oxygen mask at this altitude. But, do not take off your mask.
They do not descend lower because, succinctly, what if all engine power is lost? If that happens then the pilots want enough altitude to have enough time to try and restart the engines and, failing engine restart, to extend gliding range in effort to maximize choices of where to land.
Qualifications: expired VFR license (not a commercial pilot)
Expired VFR from above:
Think about “aviate, navigate, communicate” and add to your pilot procedure. For example, the first priority is that the pilot in command establish straight and level flight.
Also, relate that descent to things people know, such as the typical max climb and descent angles passengers experience and the maximum grade found on US interstates.
Your work is pretty good. I encourage you to pick up the textbooks used in flight school. There’s lots of ways to be a pilot without actually obtaining a VFR license, such as a recreational license or MS Flight Simulator. You can even get a taste with a type of skydive called an “assisted free fall”.