Actually last time they commented how nice it was to deal with someone who was dressed smartly and tried to communicate in Thai even if largely unsuccessfully.
On renewal did you have to supply your bank account statements and or passbook. If so they probably checked without asking you directly..
Well your experience is clearly different from mine and many others who have posted on here. On renewal they did look that the intial transfer of funds to Thai bank was from abroad (FBB code iirc).
All down to the individual IO as you present. Its a risk that you need not take by getting the visa, and as its an e visa you don't even need to be incountry to collect it.
But even with a visa the individual IO can refuse entry.
Visa waiver entry then change to retirement can still work but success does depend obtaining a Thai bank account, which is now more difficult, and having all the correct required documentation to be processed timeously.
Not ideal, and yes the out of country retirement visa can be easier, but that does require health insurance which can be a problem for some.
The in country retirement visa does not need health insurance. 'That's what the b800k is for' quoted to me by an IO.
I'm unclear as to what the £12k mentioned at the end of your post refers.
If its the Thai entry requirement of b20k or equivalent that is separate to the capital or pension income requirement for a retirement visa.
If its the pension income requirement of b65k monthly that must be certified by the relevant embassy in Thailand (which the UK and US Embassies will not do, so that option is not available to UK or US passport holders).
Yes. If you don't intend to leave Thailand in that year, just b2000.
If you change your mind you MUST remember to buy a re entry before you leave for b1900 (can usually do it at departure immigration) but if you may go out twice or more the multiple entry is cheaper at b3800 (but I dont think you can do ME at departure immigration).
If you leave without a re entry the visa is cancelled.
Very strongly suggest you thoughly check out the region you intend to stay as regulations appear to have different interpretation regionally. And there is much variety in life here.