Open fixed deposit account with an amount you want to use as a limit for your mastercard. Then most banks will give you a mastercard. (i say mastercard, because of course it is no real 'creditcard' then, because you already deposited the money in a fixed deposit account)
My certificate was all in Thai and only valid for 30 days. I have a yellow book and pink ID card, but rather difficult. Besides this Certificate, I needed a certified copy from my embassy in BKK from my passport, certified translation to Thai at Thai Ministry of Consulair affairs in BKK. Before I got it in my Amphur. But I read verry different stories about that. They wanted an original of the certificate, so that was the second after one needed for my drivers Licence. Good luck !!
Don't know for UK but Netherlands is 20 years for using them as usual. After that you can change them in "the Dutch bank" (government institute) eternal.
Most retirees have pension, which is mentioned in my first picture. All income (Pension IS an income) from abroad is tax liable. But okay, up to you. I have a big advantage of paying tax in Thailand