They are likely checking you are still in the country hence why they want every page including blank pages, not just pages with stamps

Everyone needs to apply individually. The principal person applies first then the others apply quoting his visa along with the required information

Nobody can tell you that other than the immigration officer you will stand in front of. If you're having to ask the question I suspect you know what the answer is

@John *******

no. Only Bangkok or Chiang Mai. That's why people use an agent, saves travelling, hotels etc

@Karl ******

leaving the country implies you have already stopped working at that point. Your extension of stay needs to be cancelled the day you stop working at the latest, and to cancel your extension of stay you need to show you have cancelled your work permit.

@Karl ******

I doubt you are on a visa, much more likely you are on an extension of stay. Once you stop working you need to cancel your work permit and your extension of stay but you can do it in advance with documentation from your employer, then leave the country. If you don't do it in advance you have to cancel both on the day you stop working and leave the country that day. If you don't you can be deemed to be on overstay which can get you a fine as well as impact on future visa applications

You need to be inside Thailand for 180 days in a calendar year to become tax resident for that year. If your not a tax resident they're not going to give you a TIN

It's hard to tell from what you have said. Keep away from agents if you want to sort it out. But if you didn't have 800k baht in the bank on the day your 12 month extension of stay (its not a visa) was granted then you are not going to be able to comply with the requirements for your current extension of stay. For me you have 2 options, continue to use an agent or close to the expiry of your current extension of stay leave Thailand, apply for a new 90 day Non-O visa, return to Thailand, and when you have 30 days or less left on your 90 days apply for a 12 month extension of stay. Forget about the 65k baht option until you are looking for your 2nd extension of stay at which point you will need to have a minimum of 12 months of 65k baht transfers from overseas before applying

How long were you signed up for?

Did you show how you could sustain yourself?

Whether it matters or not depends on the purpose of the transfer