Yes to all three, except maybe the max you can get out of a METV to be 269 days not 270, unless you happen to be in a timezone that is behind Thailand. It would be feasible to get 270 days if one can get a METV in Vientiane or Phnom Penh, but unless you are a resident in any of those countries, the METV has to be applied for back in Europe or wherever, and the time difference and travel time will waste at least one day out of the 270 :)

The date is clearly indicated on the stamp

You can enter on visa exempt, which is not a visa on arrival, you as a UK citizen don't qualify for visa on arrival. 30 days free of charge, if you need longer you can obtain a visa beforehand. The visa exempt stamp is awarded when you queue to show your passport at immigration.

30 days since 01-01-2017, before it was indeed 15 days, but from this date onwards, you will get 30 days. I am Dutch myself and have recieved 30 days on all of my two overland stamps this calendar year..

I believe it is the responsibility of the person where they are staying. To be honest, I have stayed at friend's homes in numerous places in the country and never had any problems. heck the place in Bangkok where I stayed NEVER even asked for my passport, I just show up and get the key. They did on occasion asked my Lao partner for his passport, but last time when I arrived alone, they just handed me the key and that was it So technically speaking immigration never knows that I stay there.

This is a sad story, I do feel for the Serbian Lady. The tour agency should have know the visa validity is only 90 days from date of issue, they should refund her

@Mark *********

Yes in fact they do. But that's not the airline's concern, they are concerned about entry requirements, and those do not include onward travel requirement when you already applied and are awarded any kind of stamped visa. And not many embassies actually require proof of onward travel either.

If you have a valid visa in your passport, there is NO onward travel requirement, the embassy might ask you if you apply for the visa, an airline has no legal ground to ask you, as the travel requirement only exists for the 30 days visa exempt stamp, if you have a stamped visa, no such requirement exists.

@Lance ******

Sorry to hear that, of course they have no right to refuse you boarding on that basis, as with an SETV or a non O there is no ticket out requirement, hence it cannot possibly be used to deny someone boarding. Big fat compensation claim would be feasible if an airline ever did try to do just that .

Yes you can, a stamped visa negates the ticket out requirement