The none O is the one you want for both retirement, or marriage. Also makes opening a bank account a lot easier. I am married to. Thai lady, but I am doing the retirement visa, as a lot less paperwork.
I did 7 visits one year, all for 10 days. No problems at all, not even questioned by immigration. But best to have proof of onward travel just in case.
they sent me an Email asking me to upload more information. When I logged in there was 3 separate links, for the statements that they wanted. I am applying using the income option.
I used my Uk driving licence on my None O visa application. I have a Thai daughter, but I have gone down the retirement route as I am over 50. I have used the monthly income over 65,000 as proof of funds. They wanted 3 months of bank statements for that.
They visa is issued from day of approval, it is valid for entry during the 3 month period. You do not have to exit when the entry period expires. You can stay for the period granted.