no, the WISE card and the Revolut Card are not"real" credit cards. They are just Debit Cards. After having spent 200 USD on the WISE card per month, you get charged 1.75% provision on each purchase and withdrawal
you should use a "real" credit card (Visa or Master) to withdraw Thai Baht on a Thai ATM. Many card issueing banks do not charge any extra fees for foreign withdrawals, so you will only be left paying the Thai bank ATM fee of 250 Baht. The exchange rate of a Visa- or Mastercard provider actually is a VERY GOOD rate - it is only marginally less than the rate for exchanging cash at a Superrich booth in Bangkok
you can apply for the 90-days Non-Imm-O Retirement Visa through the E-Visa online system of the Royal Thai Embassy London. Once entered Thailand, get a bank account opened and transfer a minimum of 800,000 THB onto it. And as soon as the money has sat in the account for 2 months, you can apply for the 1-year Extension of the Stay Permit based on Retirement
the Non-O/A visa is the "Longstay" visa. The "Retirement" visa is the Non-Imm-O visa (without "A"). I do not recommend the O/A visa for people who wish to retire in Thailand because it includes a mandatory Thai private tgia-listed health insurance after the second year. If you start out of a Non-Imm-O visa, you maintain a freedom of choice regarding your health insurance
there is an option where parents of children who are attending school in Thailand, can "piggyback" as "supporting family" on the Non-Imm-ED visa and the yearly extensions of the stay permit of their children until they are 18 years old. This is an option you must discuss with both the embassy in Berlin, and the Immigration office in Bangkok
how to you reach your conclusions? What does the bank account, once it has been opened on the correct visa, to do with his future stays? The bank does not check his visa status