technically it's still not based on retirement. It's purely based on being at least 50 years old. The translation from Thai to English is something like "visa for the purpose of living out your remaining years"
yes that's why you only got stamped in until then. If you get another year of insurance and then do another border bounce before your visa expires in November, you should be able to get the additional year.
You can go to immigration and ask if they can help you. Some offices will take both of your passports and your printed visa, make sure everything matches, and then put a small stamp inside your passport that references your old passport number. This will let you enter Thailand with just your new passport and your printed visa.
he's not on a 12 month extension so he cannot apply for "another" one. He's on a 1-year multiple entry visa that gives a 1 year stamp each time you enter until the visa expires.
A visa is used to enter a country. Yes, a bank account is required. The bank account in your home country when you apply for the retirement visa through the Thai embassy there.
Then when you use that visa you purchased from the embassy showing proof of funds in your bank account back home, you can open a bank account since you entered with a non-immigrant visa. Then you use this bank account to apply for the subsequent extension.
This is the way the process is supposed to work, and the way it does work if done properly.