actually, he doesn’t have to leave B400k in a Thai bank account. He could just pay an agent B50,000 (2,150.00 CAD) to make the bank and Immigration office overlook that detail.
In my experience, the airline asked for the onward flight. They only asked me once for an onward flight. It was 4 months in the future. They didn’t care about the date, they just wanted to verify I had an onward flight.