from what I've seen of it, it is hard work to get the STV with all its restrictions. Surely easier to get the tourist visa, and then get the extra 30 days in Thailand. That's only my opinion and I may be wrong.
When I applied for exactly the same at the end of last year there were two options. As you say you could either show proof of pension(which I didn't have at the time) or you could show 3 months of bank statements showing in excess of £10,000. This was last November at the UK embassy. But it may have changed now.
If you hold a full motorcycle licence and International Driving Permit this should initially cover you. After 90 days in country you need to convert that into a Thai Licence at the Land Transport Office. If you don't hold a motorcycle licence I think you can go and complete the test and get a Thai licence
yes I live in Udon and know AEK. That's where I went to get my medical certificate. I didn't realise there was an office there to also get a licence. I don't if it makes any difference but this was my first Thai licence and converting from UK licence.
I have an account with Bangkok Bank. Just not that well up with this modern technology. May I need to speak to them and try to get sorted. Maybe easier than keep going to ATM and carrying lots of cash.