I had similar issues in my application working freelance for Japanese firms. There is no legal requirement for a Japanese firm to give business registration docs to a non-perm employee. I informed the embassy of this, and they told me it was ok to submit what I could. I managed to get a bus registration doc for one of the firms i work for. The other one i just provided website links. I submitted non letterhead letters with a wet signature. I also get no pay slips for one contract, the company wrote that in a letter and the dates/amount of my last 6 pay deposits. i highlighted the salary bank deposits on a bank statement. I applied in person, last Dec, Taipei,
2 is ok. Vietnam has approved with a recent ending deposit of 500K and 3-6 months of statements. Wise i think is accepted in Vietnam, *please double check...i did 3 but in Taipei., no probs.
TV is ok for a one year lease, main thing is having the cash then you are good to go. Both are great options, It may take a bit longer than a week, 5 business days excluding day of submission.if there are requests for more docs then the approval time is reset.