There won’t be an option before long, it is thought that when extending your visa you WILL get a Thai tax number and have to report worldwide income such as pensions, dividends, capital gains. Thailand has signed up to Common Reporting Standards meaning they are able to access your tax records and bank accounts abroad.
Yes you get stamped in for 60 days you can extend this another 30 days at immigration. You then leave Thailand and re enter and get another 60 day stamp