It is correct that the train stops at the border and then continue on the other side of the border. But you have a train/bus ticket for the entire route and in that way it does not necessarily have to be a plane ticket.
"Is there a direct bus between Bangkok and Cambodia?
Yes, there is a direct bus departing from Bangkok Mochit Bus Terminal and arriving at Phnom Penh. Services depart five times a day, and operate every day. The journey takes approximately 12h 30m."
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"Evidence of travel to Thailand (air ticket paid in full).
A minimum of two inbound and outbound tickets are required for multiple entries visa."
If he owns a condo or leasing the land and owns the house he is his own landord.
If a foreigner in Thailand has a foreign guest staying in his home for more than 24 hours he must also fill in TM30
"The notification of residence of foreign nationals is made by the manager of licensed hotels according to the hotel act, owners of guesthouses, mansions, apartments and rented houses using the form TM. 30."