Nobody gives a shit about TM30. 25 years going to Thai, never heard of it. May come into the play if you are in Thai longer than 2 months, I have never been in Thai more than 2 monts, 3 times a year
Reading the news, unusual high value money movements trigger their (the banks) algorithm. Thais affected, mostly, are those humble street market vendors with QR code, who sell food 50-100 THB and all of a sudden, they get 100 thousand baht into their account that disappears within 1-3 minutes.
Japan: It took me 2 hours, in person, at the branch, to change my address with the biggest Japanese bank. The change was - I bought my home in Japan, all documents were updated (ID card, Tax file number, driving license) by government bodies. Still.
For simplicity, Thai Airways ticket one way Tokyo - Bangkok is 10,000 THB (return is 20,000THB).
Return as one way is also 10,000 THB.
Those tickets are the cheapest. Any change of dates - 200 US$ fee.
Flexible tickets (dates change) are 40-50% more expensive upfront.
Edit: say, you are entering on 60days visa exemtion or on Non-O 90days. Then decide to xtend for 30 more days. You are in for that fee as you would have to change your return date.
The way around it may be to buy the initial ticket as the cheapest one, Then buy, at the same time the more expensive, independent one way return ticket with a flexible date.
If you buy them as return at the same time, one transaction, the onward the chepaest, the return flexible, the rules of the cheapest one apply to return ticket as well.
I hired a lawyer, not an agency. There were more hoops than what you said (could be specific to my City Council, could be less with yours). Certified my Australian passport, then the lawyer went to Immigration. Then with me and my wife to the Samut Prakhan City Council. Took 1 hour, City Council copied whatever they could.
The lawyer ( a wonderful mature lady, great English) came to the nearby Starbucks, with her assistant, with portable all in 1 printer, scanner and copier.
3 weeks later, the lawyer said my yellow book is waiting on me.
Defeats me, I am the owner of the condo, my wife and our daughter (Thai nationals) have their Blue Book. My wife has to sign for my Yellow book.
Well, Thai laws.
Wife and myself live in Japan, daughter in Australia. None of us living in Thai.
The price for the lawyer's service was 15,500 THB. She was great, I may have some other legal dealings in Thai (my will, for example) I would use her services again.