at this point if I were you I would avoid airports.
Second I exit and go to my embassy to get a new passport. Yes it links to your old passport but when you have a line of hundreds of people the immigration officer only looks at the stamps in your passport not your history. They will look at your history if you get called to the side.
I would contact the visa run company that leaves from OnNut Tesco Lotus parking lot. They will be able to tell you if they can do a visa run safely.
I think it is impossible to give you any clear answer because we don't know your lifestyles, age, standards of living and city where you plan to live. My health insurance covers up to 500k usd w a higher deductible, I am healthy in my mid 40s so my insurance is only in cases of emergency cost 20k baht a year.
Cost of living in Bkk is much higher than other parts of the country. Do u plan on living in bkk or another province?
A descent 3 bedrooms condo is about 40k baht in the city in a good area.
Electricity if u can live without AC is around 1000 baht. With AC running 2500 baht and up.
I chose to live in the center of the city so I don't need a car. Traffic is truly awful.