when departing on a trip to thailand you better be ready to show the thai passport to the airline ticket agent or they wont let you board as there is no visa in the us passport
tod on here and ubonjoe on thaivisa seem to have the advice on retirement visa that is easiest to comprehend. 90 day Non-O to start and apply for 1 year extension once you arrive and get the money in the bank and/or the proof of income from your embassy