All within 30min to 1h if you want. Depending how good timing is.
If you go to Vientiane ofc longer. The Train goes to Vientiane. So if you want the train back to BKK you have to take the train to Vientiane. I'm assuming the train waits for you guys at the border? Or you buy a train ticket at the border and wait for the train to come in the opposite direction? I'm not sure how it works it's very new.
Yeah, I know. I'm married. But discussion was with a dude that thought DTV is limited to 450 days within 5 years and who thinks visa exempt entry is a proper visa. It was more of a discussion about tourists and their options.
Call the border, they will tell you. I live near the border, that's what happening in Nong Khai atm. Everyone is allowed to come in unlimited. Geez. You claimed that every border have refused entry to people, which is factually incorrect. "It happened in the past", no, it didn't, only in certain border like Poipet, not ALL as you claimed. Nobody has ever being refused entry in Nong Khai or Mukdahan, that's a statistical fact. You won't even find an exception.
Geez you are bad at this. A visa can only be obtained at a consulate OUTSIDE of Thailand. A visa exempt can only be obtained at the border or airport from INSIDE Thailand. You don't understanding terminology, no wonder you are lost. No offense but these are basic 101 stuff that only newb don't know about.