Anonymous participant you can give them statements from both accounts and add a letter explaining you have two accounts and how the total amount adds up to the requirement
yes everything converted to PDF, then merged, then compressed. 1 file for location, 1 for financials and 1 for the Muay Thai. All files were well below 1MB. I used βI β₯οΈ PDFβ for this.
The application system tells you at the very beginning of the form (where you have to upload the biodata page of your passport), I think it was 6 months
maybe if you fly same day as arrival, they could see it as a connecting flight. Make sure to add your boarding pass for both flights, hotel booking in Hanoi to the application. But the biggest issue is that starting Saturday the whole country shuts down for a week for Tet (lunar New Year) so if you apply today, you won't be approved until 5 or 6 February at the earliest