Best bet is to go to Vientiane, make sure you have bank statements with a few thousand dollar or equivalent in thb, a flight ticket out of the country, you are dressed properly and don't look like a back paper plus all the other usual documents. If you don't get a 60 day tourist visa there then ask around outside the gate for a transit visa. There should be some Lao guy who can get you a 30 day transit visa. There was another post some days ago here with more details about the transit visa.
No worries, just leave this country where you are not appreciated in anyway. Plenty of better countries to live in. My condo building is half empty now, all foreigners left.
much more hassle IMO. You run the risk to be questioned by stuck up immigration officers at the airport unless you plan to stay a couple of days in Malaysia.
To stay an extra month it would be easiest to to a border run to Myanmar, about 4 Hours drive from Bangkok and cost 2000THB. Not sure what your nationality is so check beforehand if you get 30 days or 15 days when entering Thailand again.
can't change it. Was a mistake on my side as I had a ED visa expiring on 14.October so I wenn du Cambodia on 11.October because of convenience. I was under the impression that they would give me 30 days starting from 14.October as that when my ED visa expires. My fault