Just post a situation here.
One Chinese guy(not me) was just deported by immigration officers at Suvarnabhumi airport as he was found he had a overstay record of 62 days in kingdom. No booking conformation of hotel, no return flight ticket even if he has a valid tourist visa this time. Currently he was arranged to stay at a small room(I promise you it's not comfortable at all) and he has to buy tomorrow flight ticket to China under his bill. I am understanding how important we behave according to the regulations and law of the kingdom of Thailand.
TLDR : Answer Summary
A Chinese traveler was denied entry at Suvarnabhumi Airport due to a 62-day overstay record in Thailand. Despite having a valid tourist visa, he lacked proof of accommodation and a return flight. This incident highlights the strict immigration regulations in Thailand that require travelers to have a return ticket and proof of funds, irrespective of the visa status.