In the world order, You are either a Tourist, a refugee, a resident, or a citizen. I don't actually think Thailand considers the Retiree as a "Resident". Just a tourist with a longer visa duration.
In most countries, resident status can be attained when you get married, work, have a child, or attend school. Once any of that is done, you will be re-evaluated.
I have read all the tips over the last couple of years, but the common thread over that time is:
1. Different Customer reps in the SAME branch will have completely different results, so it really IS the luck of the draw.
2. Bangkok Bank seems the best to try first.
3. Having a passport is usually a must
4. Go with a Thai person you trust. This gives you 50% chance instantly!
I got a savings account and debit/BTS card without needing a visa, but she saw from my passport that I am there often, and she also wanted a foriegn account from where regular funds would be coming from. My gf did all the talking.