You need to go to a bigger branch such as in Central, with passport and certificate of residence. I've opened both Kasikorn & Bangkok bank accounts on a tourist visa in the past, however Bangkok bank didn't give me online access with a tourist visa.
Everytime you apply for a 'long' visa every year yes, not so hard though. If you're 60+ many places do a retirement visa without proof of $, hard to say without knowing your full circumstances.