The photos are for a marriage extension, not a retirement. You don't need any outside parties to open a bank account. While different branches have different requirements, a valid passport and a condo lease (even an airbnb booking) is enough to open a bank account, just saw someone last week do it in Phuket.
The only thing you're landlord needs to do is do the Tm30 and give you a signed copy of his ID card, which you should have had with your lease anyway. Remember, you can be staying in a hotel and apply for a retirement visa/extension.
If you're in Phuket you DON'T need an agent to do anything for you. Bangkok, maybe. There's like 3 people a day going through Phuket immigration (compared to the 5000 a day in Bangkok).