In HCMC city yes. Holiday and now weekend. They might be backed up next week. I would guess 10 business days. But book a changeable fare then you can leave when completed
Then apply. Might be risky but it doesn’t say you need to be married a specific period of time.
Your other idea. Apply then transfer to his account could work unless they ask in the future to see bank accounts. As of now not required if you leave every 6 months.