find a Thai person who is willing to report him anonymously to immigration for having illegal workers. You should stay out of it personally. maybe best to simply walk away

but the Monday queue is always bad- why not spend a night in Vientiane and go on Tuesday?

it is doable from Udon- you might want to leave at 5:30 just to be in the safe side

thqt is why Nongkai is a better choice- you save at least 45 minutes, possibly an hour and a quarter

spend the night in Nongkai on the river- it is much nicer and much more convenient to get to the embassy in the morning.

whatever works... it is likely the cause of his being turned away at the airport ; I know several people in the States who has the same problem- I was flying once from Taiwan and the airline wouldnt sell me a one way ticket- I had to go to the Thai consulate and explain to them that I was headed for Cambodia by land and they wrote a special note to the airline for me.

have him buy any cheap air asia ticket out of Thailand for sometime before the visa expires- he can throw it away or use it - probably no return ticket is the reason

yes Savanaket