Anonymous participant 385 that will get your application cancelled if they find out. You must remain in the jurisdiction of the embassy for the entire application process. Pretend they have your passport like the old paper application process.
Anonymous participant 629 you cannot cancel a visa. It's the work extension, education extension, or marriage extension that is cancelled, not the original visa, because it cannot be cancelled. So the DTV is not like the others.
it hasn't been available inside of Thailand for a very long time. People used to go to one of the nearby embassies to get it, but with the new evisa system no embassies sell it anymore.
400,000 is the amount of money a foreign man married to a Thai woman needs to apply for a marriage visa. If your wife is not Thai, then it's 800,000 for each of you, regardless of when she comes.
Then you shouldn't have any issues as long as you can show that the money in your Thai bank account was transferred as an international transfer into Thailand.