never seen a DTV are you serious why would you say that. Vientiane is one of the main places to apply for a DTV I did mine there and crossed at nong khai.
haven't wouldn't couldn't 2 days in bkk is my limit and it's 2 days to long. Never taken me more than 5 minutes to do a 90 day report and it's free. But hey it's just the way l fly
If your work permit is cancel or not doesn't matter if your visa is single entry it is canceled when you leave. It's up to your company to cancel your work permit. Then you can re enter on visa exempt or whatever
oh yes I have been there before they are very good. They will help you if your unsure just ask. They will know by the way you act and ask questions that you are genuine person. Enjoy