You can use Tagthai, True money, and another app (I forgot the name, starts with an M) to scan pay. As for getting cash to Thailand without fees, depending on where you friend is from, they might be able to get a bank account with debit card back home that refunds ATM fees. In the US Schwab is a good example.
This won't work. When you go to immigration the 2nd year they will want to see a 12 month bank statement, for 2 reasons. First they will be checking that you did the monthly transfers, and 2nd they will be checking that you met the financial requirements for the previous year's extension, which is that you must keep the 800,000 in your bank for 3 months after you received the extension and never let it drop below 400,000 the rest of the year. If the op uses an agent, he clearly will not have met those requirements, and he will be denied the extension altogether for failing to meet those requirements. Some offices even tell the person that they've technically been on overstay from the day their account stopped meeting the mandatory balance their extension required. This is why people get stuck using agents year after year, because they cannot prove they met the previous year's requirements.
When you got your education extension, you signed a piece of paper that said you would notify immigration of any change in status. Ending your studies is a change in status.
You need to get a letter from your school that states the last day of study (I would make it a couple days after you plan to leave Thailand if they will do that) so you can have some leeway. Then take this letter to immigration about a week before the date on the letter, and they will cancel your extension and then stamp you back in until the date on the letter.
If you fail to do this, and you go to immigration in the future, for example for your extension based on your non-O visa, they can charge you 20,000 baht for failing to cancel your previous education extension. They can also prevent you from applying for your extension until you officially cancel your education extension, even so far after the fact.
Not for the first year, no. Immigration in Thailand will only accept 2 things for your first annual extension, and that's embassy certified income (Australian embassy does not do this) or 800,000 in a Thai bank account. Since you cannot meet the 800,000 requirement your only other option is using an agent. But now agents cannot help you if you arrive as a tourist, so you need to get the non-O visa before you travel to Thailand. And that also means you'll have to continue using an agent since you can't prove you met the financial requirements in the previous year.
If you get the non-O visa based on your monthly income before you go to Thailand, you can pay an agent to get you the annual extension without showing money in the bank.,
Yes, exactly. They will put an entry stamp in your passport each time you enter Thailand, but the visa itself will be the PDF document. If you get it in Bangkok, then the visa itself will be in your passport, and you'll also still get an entry stamp each time.
Honestly the biggest difference between the two is that you are going to pay more money for the visa from the embassy. In Thailand it's exactly 50,000 baht that you pay directly to the immigration office. If you get it from the embassy, they charge a few hundred dollars more.
You cannot leave and return on visa exempt because you have a valid multiple entry visa. If you leave and return you'll just be stamped in on your DTV.
The law that created the DTV specifically says it can be converted to another visa type inside Thailand. You'll need to check with your local immigration office to find out details and their willingness to do so.