I had five work perments from three labour offices while I was on an extension of a non O, on each extension it was clearly stamped RETIREMENT, but there was never a stamp employment prohibited.
Best thing is to get a Non O based on marriage, from your own country I think you can get a one year multiple entry, but you will have to do an in and out every 90 days.
For your ฿20,000 is that per person or for two if traveling as a couple? Also do travelers cheques count, or do they even exist? Just an aside does Thailand not know this is the twenty-first century and most people use ATM cards when traveling?
I got that response 7 days after I registered. That was last Saturday, still no E mail. I have to go to immigration for a 90 day report next Friday, do if I haven't got anything by then hopefully they can straighten things out.