the renter is not find. They try to get you to pay the fine as you can not proceed whilst the fine is outstanding. You are not liable for a fine that is the owners resonsibility. But you can not proceed until the fine is paid.
It only becomes an issue you you wish to extend your stay or you are subject to a 90 day reporting rule. It is not well managed. I applied for a residency certificate but that information was not transferred to the Immigration database. When I went to apply fr an extended visa they said I had to be registered and asked that owner needs to fill in the TM 30 form or pay a fine of 1600THB. As me lease expired I booked into a hotel and the hotel registered me. Went back the next day all ok. No fine, (Which is payable by the owner)
I wish they had an online app to fill in a register the departure cards Most if not all the information is on your flight booking. It could be done with a QR Code that brings you to a page to be filled in. Ir there could be link to your flight booking which has most of the data.
What are the statistics on refusal of entry? I have been traveling to Thailand on a regular basis since 1991 and never had any issues related to onward travel. I tend to buy a one way ticket and before my visa expires I find another chap flight home or else where. You can also get good deals on buss to Laos or Cambodia . If I am asked I just tell them my plans. With fewer flights to Thailand as a hub city it is in Thailand's interest to encourage one way flight options. Cheaper way to travel if you are an experienced traveler. More fun as you can change options.
With the high number of cheap frill air fares and the inability to change dates more and more travelers are opting for a one way ticket. One tickets also allow travelers to travel overland to other onward destinations
Stay in a hotel near by and go early Ir is a good city. Dinner on the rover Best part is your Thai mobile works. I stayed at the Family hotel it was good value. Not sure how close it is to the Thai Embassy, Take your girl friend, Good holiday break