I have. I had a problem with renting, opening a bank account, transferring money, getting a bank note to pay an overseas fee without a contract and a rental contract.
Teachers at my school and the school itself acknowledged these and other issues (driver's licence) and after admitting that they did not have a licence to hire foreigners stamped my contract at their head office. They also paid to translate needed documents to English. I was working illegally without my knowledge. My first job. Work permit docs in the drawer in case anyone asks.
As for renewing my visa every three months, my wife and my marriage exemption visa dealt with that. I can't imagine packing everything dear to me for the visa run every three months just in case I couldn't get back in. I bet it costs more than the $10 I paid.
How did you get around opening a bank account without proving you were in the country legally? You probably can't say because you would be counselling others to break the law here. There is no other way.
Just last week I had an issue leaving VN because the ticket agent at the airport wasn't familiar with the new residency permit. In other words she needed proof that I was in VN legally just to process my ticket and give me a boarding pass.
I'm legal here and it took me most of an hour to prove it to immigration and the freaking ticket agent. Last Wednesday. Eight days ago. It turned out that that the new residency permit was sufficient. It seems that that's what it's for. Can't get that working illegally.
How did you support yourself the last eight years mr. -------. Can you answer that question? Can you prove it legally?
If they want to get you they can.
Eight years of tourist visas every three months wouldn't pass that scrutiny. 'How did you support yourself in VN?'. I've heard of this from Korea back when people were working illegally there. They get you on the way out.
Working illegally is a mug's game.