@Lynne ******

you need to get an IDP in your home country (if in the UK, you get them from the post office)

I have been able to do this with an Irish passport and German account (not in Vietnam, admittedly). Can't see that it's against the rules. It's more about proving that it's your money and that you have access to it. You say you have permanent residence in Mexico? If you have documents to prove that when you apply just in case, I can't see you'll have problems

You don't need a visa to attend a job interview. You can just enter on a visa exempt stamp, which will get you in for 30 days. If you successfully get the job you would have to obtain (most likely) a non-B visa somewhere outside Thailand. This can be a neighbouring country

You don't quite need to be a permanent resident in Laos. You just need a work visa there. I have got an METV this way. However by the sound of it you don't have that....?

Most likely yes - you're allowed two visa exempt entries by land per calendar year. The only caveat is that I think this doesn't apply to some nationalities when entering from Cambodia. The gurus of this page will advise on that, but otherwise, yes you can.

Beware that Mondays and Thursdays are the busiest days, so if you want to minimise the queuing, try to go Tuesday or Wednesday

@Dennis ******

yeah, that'll be fine. You will receive your passport back the following afternoon

You can Take Lao Airlines to Bangkok at 18.30. Usually costs 3,000b, but includes luggage and a can of Beer Lao on board

Right, the best and only way to do this, without flying the night before, as others have said, is to take a 6am(ish) flight from Don Mueang to Udon Thani (Air Asia, Lion Air and Nok Air all have options), then a van from Udon to the border, then once across the border, a taxi straight to the Consulate (not the embassy!). If you do it this way, and assuming your flight is on time, you can be at the consulate for about 9.30am.

As for hotels, there are a few places within walking distance of the consulate, but I would suggest staying in the centre and getting a tuk tuk there, as in the centre you have far more eating/drinking/night market browsing options. The area around Consulate is a bit of a deadzone at night.

I have tried to do this and can confirm that you CAN NOT do it. You can 'passport switch' by air to and from most countries, including between Thailand and Cambodia, but it is not possible by land. So if you need to passport switch for whatever reason, you need to fly.