I’d suggest you look up if there’s a thai embassy in Qatar and then see if you meet the requirements to get an AO visa. If you can, you will only need bank statements to show you have 800,000 baht (equivalent) in your account (not in a thai bank) plus the other requirements of course
They are not related. 90 day reports only if you stay in Thailand for that period. You can also leave Thailand before it’s due and when you return it resets so it becomes 90 days from your return date.
You don’t need to any of that if you get the retirement visa in your home country before you get to Thailand! Plus you can get almost 2 years from that one AO visa 😄. Easy enough to get a thai bank account when you’re here too