Look at the Non-O (retirement) over 50 visa which has no insurance requirement. Check the Thai Embassy website in Switzerland for their requirements as they will be approving the online application. Other options include the LTR Visa (wealthy pensioners).
Yes, your missing the specific requirements for the visa you are applying for listed on the Embassy website, the Embassy that will approve (or reject) your application. If you're in the UK, for example, look at the RTE London website before uploading to your online application.