you fell for Immigrations bad English and wrong wording. . . . . You need to be either on the 90-days stay permit out of a Non-Imm-O visa type, or you need to be on a "1-year Extended Stay Permit based on Retirement". You are NOT a permanent resident of Thailand if you have any of the two mentioned stamps. All you got is a "stay permit" for Thailand, but not a "residence permit". The "Wohnsitzbescheinigung" ist just a letter from Immigration certifying that you are living under address XYZ. We call it "certificate of residence" and this is what is needed on most banks to get a bank account opened. . . . . .you could only bypass the "certificate of residence" if you hold a yellow house book and a pink ID-card. . . . . . . A "residence permit" is something else, it is a blue/purple passbook that says "PR-Permament Residency", and the hurdles to jump through in order to get one issued are very high
no, on the contrary, they wouldn't care less. They make you prove everything when you visit Immigration and apply for the extension. I suggest you join the "Digital Thailand Visa" Facebook group, they are specialized on this subject