When the 800k baht requirement was put in place (2018 I believe), it was to ensure those over 50 could pay for medical expenses they may incure. That's why the Non-OA that doesn't require 800k baht requires thai health insurance.
Never said it was a visa that worked for you, just asked what you'd define as a long term visa. A Non-O based on marriage or retirement is only 90 days, half the time a DTV allows you to stay. You also cannot work with a Non-O by itself.
First of all Jimbo, I aint confusing a fking thing. The DTV is a 5 years visa, you're given 6 months to stay per entry. Both the visa validity and permission to stay is long than the most common "long term visa" a Non-O based on marriage or retirement.
Non-OA can only be applied for in your home country. Assuming you're on your initial Non-O, yes you can leave the country but you need to buy a reentry permit.