The thing he's referencing as must be printed is specific to Laos. After you apply for the visa online, you must wait for them to send you a confirmation with barcode. You print that and take it to the embassy or consulate where you applied between certain morning hours to submit payment for your visa application.
Same criteria possibly, but not the same procedure. The embassy and consulate in Laos is the only place where they will send a confirmation that you print and take to the embassy to pay. Everywhere else accepts online payment for the visa.
You should edit your post to include the specific Embassy or consulate that you used, whether it's Vientiene or Savannakhet.
There's no such thing as a multiple entry non-O visa anymore.
Are you actually on the 90 days of a Non-O visa, or are you on 1-year extension of stay?
I'm assuming you're on an extension of stay because you said you want to go back for "a few months" and a 90-day stay would not cover that period of time.
If you're on the 1-year extension of stay based on retirement, what you need is a re-entry permit. What is stamped on a visa is irrelevant because the visa is void as soon as you enter Thailand it's used up.
So check your passport and see if you can find your 1-year extension stamp, and if you can find a re-entry permit that's valid until the end of your extension. If you have that, then you are good to go. If you do not have it, then you need to purchase one from either your immigration office at the airport on your way out.
Some people already have a bank account before they arrive with the non-O from being in Thailand previously. And next year you'll be able to apply early. How early is up to the immigration office you use. 30 days early at most offices, 45 days early at some.
Someone just reported being asked to show 20k with a DTV yesterday. DTV is a tourist visa. ANY tourist entry can be asked to meet the tourist entry requirements.
I think you need to look at your passport again. The "under consideration" stamp will have a date on it. The date on the stamp should be your temporary extension until you receive the full one. Though normally for a conversion, it will still be within the days of your normal permission to stay. You should also have received a blue slip of paper which is your receipt, and that may have the date for you to return as well.
This is not a new rule, far from it. It has been in place for many years.
You do not have to show 20,000 baht. But you are required to have that much to show if you are asked. And it does not have to be Thai baht, it can be in any currency as long as it equals 20,000 baht or more.
There are 3 things required to enter Thailand as a tourist, and these are the same as always.
1) Proof of funds
2) Proof of onward travel
3) Proof of lodging
The rule on the amount is if you are entering visa exempt (without a visa) or tourist visa, you are required to carry 20,000 baht or equivalent in another major currency, or 40,000 for a family.
If you are entering Visa on Arrival (not many countries, they apply for and pay for a visa at the airport) then they are required to be able to show 10,000 baht for an individual or 20,000 baht for a family.
A lot of them change their visa processing when it gets into high season, and prioritize based on the flight information provided. As the OP said, the vis came in the day before the flight. That's because that's how they do it when they're busy.