I am saying if your embassy will not verify your income and the OP is an Australian citizen and the Australian embassy will not issue a verification letter. His other alternative is to either use the banked method of 800,000 baht in his Thai bank account, or have an income of 65,000 baht minimum going into his Thai bank account every month.
Health insurance is only compulsory when you are on the OA visa, you said in your previous posts that you will be applying for the Non O visa based on retirement, you do not need to show insurance for that visa, but it is always a good idea to have insurance anyway.
A few of my friends use AXA they say the policies and premiums are quite good. I use Pacific Cross, but I wouldn’t recommend them, but too late for me to change unfortunately.
If you are from a Country where your embassy will not issue you with a verification statement regarding your income, Thailand immigration will not except any other verification in regards to your income. You can either use the banked money method or the monthly income method.
Every bank and every branch can be different, on a tourist visa it can be difficult, but not impossible. Some may ask you to purchase insurance before opening a account with them. But basically you will require a certificate of residency from your local immigration, that in itself can be challenging on a tourist visa. Good luck, but I would be trying Bangkok bank, most people find them more accommodating.