I'm not a tourist 🤷♂️ I'm "allowed" to use online banking with my business account, but I'm not allowed to register the same account on the K Biz app. This post has nothing to do with being a tourist trying to operate a bank account
I would check Bangkok Bank. While a bank account on anything other than a long term is difficult, I think that owning/buying a condo meets the criteria on a short term visa.
You would register your marriage at the local amphur office. If you have been married before, you will documents from Australia showing you are legally divorced. You will need a certified copy of these and a certified copy of your passport, ith of which you would get from your embassy here in Thailand. Once married, you can the apply for your Non-O, and you will need to have ฿400,000 in your thai bank account. If you dont have a thai bank account, that is where you will run into difficulty. Good luck