ThoughtfulLychee5096 You maybe able to open the account in Thailand but they do not deliver debit cards to Thailand. Can you use your client's/friend address to open an account?
It is useful to have them printed in case of needing to refer to something. Or have them available on your phone. Be ready to show your bank account balance.
It is voided. Some have had their DTV rescinded on arrival for the breach of application. Some have got away with it but this is your 2nd application so not worth the risk. Email the embassy about the progress of your application.
You need to show you work remotely for a non-Thai firm. it does not matter how much experience you have or if you are a permanent employee, freelancer or self employed.
5 day hotel booking should be fine, I was approved with a similar booking. Triple check everything applying in Vietnam. They are tightening up on approvals.