this is the correct answer, no one knows how many times you can re enter, but I guess if immigration suspect anyone is using this method to live in Thailand, they will refuse a further visa.
yes, the airline or passport control, may ask for Proof Of Onward Travel within the 60 days, simply proof that you have made arrangements to leave, Jve never been asked, but my friends have.
yes I have been told that has changed recently, I opened my Bangkok bank account 3 years ago, and they didn’t even ask about visas, just a passport and proof of accommodation.
yes, the USA are on the list, simply turn up at the airport and get an exemption visa which will last for 60 days, before that expires go to an immigration office and get a 30 day extension, the 30 days starts from the last of your initial 60