each immigration office will have different requirements. Generally your passport, TM30, passport photo and application form. Some offices charge and some don't.
Owning property does not confer any right to stay in Thailand. The banks care about your visa and your permission to be in Thailand, not about your property.
Immigration offices are quite clearly not wanting to give DTV extensions. You just need to read a few posts here about them making crazy requirements, and then once you meet those requirements they add new ones and then tell you to just leave Thailand and return.
Immigration offices DO NOT want to give extensions for DTV. Each office can set their own requirements and most have made it all but impossible to get a DTV extension.
If your address is in Bangkok, and you have a DTV visa, Chaeng Watthana is the only office for doing 90 day reports. The other offices are for different purposes and not available to you.
Has nothing to do with politics. The laws recently changed in Thailand holding banks responsible for all fraud and scam losses. They are hedging their bets and getting rid of all risk.