The requirement for the Thai retirement visa are somewhat less onerous these days. You do have to be over 50, however. The 90 day reporting requirement can be met by mailing in a form 15 days before your due date. I have never gone in personally to do the 90 day report myself. Exiting and reentering the country counts as a 90 day report and starts the day count ticking for the next one. The Thai gov't requires for a renewal of the retirement visa that you show a Thai bank balance of at least 800,000 baht ($27,327) for 60 days before renewal. After the renewal is approved you can do what you want with the money until the next renewal time comes up. Some other countries, like Malaysia and Ecuador, require that you maintain a minimum balance all year round. Most countries, like India and the US, don't have any retirement visa option at all.
With a retirement visa and a multiple re-entry permit, you can come and go as you like. I am on a marriage visa which has slightly different requirements from the retirement visa, but the process is the same. I go once to immigration once a year for a morning to apply and then come back a month later to pick up the visa. So, the Thai retiremement visa seems pretty easy to manage to me.
The Phillipine visa looks to be the gold standard for easy visa requirements. However, there are other disadvantages to the Phillipines, such as crime.