the benefit of the OA these days is that you can easily open the bank account with it whereas with the O it's only a 90-day Visa initially and then you have to bring in your money within 30 days so that it can season for 2 months before applying for the extension.
The other benefit is you don't have to bring the 800k over for 2 years. Then you could just go off the OA and apply for a non-O and save yourself all the insurance money and hassle
Fill out TDAC 3 days or less before arrival. You do your 90-day report at the office whoch has jurisdiction over where your most current TM30 is filed.
First cancel your work permit and take the paperwork to immigration to cancel the Visa. With a letter from your employer to the department of labor you can usually do this a little bit in advance.
If you have the 800k then I'd just get a 1 year non Imm OA in my own country then come here, easily open a bank account since it's a long-term Visa, then move my money over here and finally let that visa expire and get a non-o and then extension.
as far as your conversation with the consulate, you have to ensure that they completely understood you and where you're going and there was no miscommunication for instance maybe they thought you just intended to travel to another state. Then again you can look at the big picture it's only 10,000 baht you're risking and you have a friend's wedding to attend to.
DTV’ER possibly take new pictures of better resolution and then combine them all into a single PDF for each category, making sure it's within acceptable size, and if not, compress it from there. Use Ilovepdf.com