It’s great that you are starting your research, but it’s sad that so much information is posted as fact when it’s just not accurate. For example - DTV gives you 180 days per entry, unlimited entries; DTV is not always simple to obtain. It can be IF you qualify; DTV you do NOT need employment in Thailand. Employment in Thailand is forbidden but remote work is allowed.
you mean the 60 day visa exemption - this is NOT a visa. This is part of the trouble - people don’t describe accurately which visa or visa exemption they have.
I can’t see how you would expect to live for up to 5 years on $60,000 of savings plus paying for your medical treatment. Being unemployed and only having that amount of savings sounds very much like you are planning to work to live.
You said: "Bottom line: The laws of Thailand are forcing me to take serious risks with my health, likely to some level of injury degrading my quality of life temporarily, and possibly permanently and critically.". That is just nonsense. You have travelled with a pre-existing medical condition - your lung injury. You don't state if you have medical insurance. Knowing your medical condition you chose to travel. If a 30 minute car drive is going to put you at risk what will a multi-hour flight in a plane do? Don't try and blame the laws of Thailand - admit that your own decisions have put you in the predicament you are in, take responsibility, and work forward from there.