they can, but then they only get 90 days in Thailand before they have to apply for the extension which requires 800,000 in a Thai bank account. With an OA visa you can get 2 years in Thailand without ever needing a Thai bank account
every building will be different. I've lived in buildings that feel like a ghost town and I've stayed in buildings where I have to wait ages for the elevator because there's so many people.
My last condo was at On Nut and I paid 15,000 baht per month but it was for a 1-year lease. Serviced apartments would be an okay option that shouldn't break the bank.
You can do either, but it's better for you to get the visa before you travel. It makes it much easier to get a bank account which is all but impossible without a long term visa, and you must have a bank account for both the non-O visa if you get it in Thailand and for the 1-year extension.
Also if you get a non-O visa in Thailand the only place you can get the 1-year extension is the same immigration office you got the visa. If you get the visa from the embassy you can apply for the extension wherever you're staying.
In Thailand, ANY work requires both a non-immigrant visa that allows work as well as a work permit. They consider it "taking work from a Thai person" even if it's not for pay. If a Thai person can do it, then a Thai person should be doing it is how they see it.
You're completely wrong. Embassies are under the MFA which is a COMPLETELY DIFFERENT government agency from immigration, which is under the department of the interior. The 2 agencies do not communicate and have no idea the policies of the other. If an embassy EVER tells you anything about immigration, do no listen to them because they will tell you wrong. And if an immigration officer ever tells you anything about an embassy, do not listen to them, because they will be wrong. The two basically have nothing to do with each other.
yes, they are required to have a hotel license if they rent for less than 30 days. Mostly not a concern for people that are using them because they don't need to go to immigration which would require a TM30. That's what is difficult since many AirBNB don't want to file a TM30 for customers. In the past when I used Airbnb and knew I needed a TM30 I would message the listing to ask before I booked it. But Airbnb is also very expensive.
An empty room that is rented short term is now no longer available to show to customers or to rent to a long-term customer which is what the landlord wants. So it doesn't benefit them to rent short term. Most people that want a room in Bangkok want it in less than a week. I've never waited more than 2 days from the time I viewed a room to signing the lease and moving in.