If you're income could be considered remote then why would you use the soft qualifications. The DTV has nothing to do with retirement age. Just prove you've got the ability to earn income remotely, have a minimal bank balance and a few other details and done... 5 year multi entry visa.
I do not see it written that an extension costs 10k baht but there is debate on that depending on who reads the same document. When I read it, it says 10k visa fee. No where does it say anything about the extension cost but who knows at this point. No one has gotten an extension yet so let's see what happens in real life.
Meanwhile, every time you enter you should get 180 days.
Netflix tracks your login location and the content is different for different countries. So when you're in Thailand you access the Thai version of Netflix. It has to do with the content licensing rights and which countries Netflix has paid the content creators to be able to access the movies.
So when you're in Thailand, the content available on Netflix is geared more to Thailand and less American content.
You'll still be able to access Netflix but view a different catalog of shows and movies unless you use a VPN that tricks Netflix into thinking that you are actually in the USA (or whichever country you prefer). When using a VPN you can choose a server in the country you prefer.
This also helps with banking, some government websites, etc that track location for security purposes etc. If you watch videos on Amazon Prime this is also the case.
Netflix and others can often see through a basic VPN or see that you're using a VPN. Some vpn but not all have a way around that. Search Google for articles on it. Here is an example.