The 500,000 baht they want in the bank can be spent after you get the DTV visa. You need the 500,000 baht when you re-apply for the visa. You can get an agent to help you with setting up a thailand bank account in Pattaya. I am planning on living in Pattaya. It appears to match our kind of lifestyle. Its close to bangkok. If my wife wants to go shop, she has all the shops in Bangkok to go to... :)
Most of the other visa options require you to have passive income or a pension. The exceptions are the student visas. I can't speak intelligently about those. I never looked into them. The DTV visa is an ideal visa if you have an online business that you can work from Thailand. In my case I will be working my life insurance business, and eventually 5 other businesses remote from Thailand 🙂 I will need to be on USA time since my clients are US based.
You misunderstand the DTV visa. You have to do a run for the border every 6 months. Its a multi entry visa. Every 6 months, you need to leave for 5 minutes and come back to Thailand. Thailand stamps the visa for 6 months. You can do this for 5 years. You can renew the DTV visa in 5 years. "The Destination Thailand Visa (DTV) is a visa that allows foreign workers, digital nomads, and freelancers to stay in Thailand for up to 180 days per entry for five years. It's also known as the "digital nomad visa".