As always, excellent post.
Not according to the government. I was a waitress many moons ago and asked them why servers get paid less than minimum wage, thinking that tips (mostly undeclared) would be the answer. They told me it had nothing to do with that and was based on the type of work being performed. My then boyfriend's good friend was a tax lawyer and explained to me that if I claimed 10% of my overall wages as tips the gov't would leave me alone and they did. Trust me when I say that we relied on our tips, not our wages to survive. I don't know at what point the government started making servers declare all earnings, tips included, but it certainly has something to do with technology and the fact that most consumers don't deal in cash anymore but debit/credit, showing a record of tips given.
When it comes to escorting, I have a numbered co./sole proprietorship and an accountant/small business consultant that has classified me as an entertainer. He explained to me that as long as I file every year on time and pay on time the gov't will leave me alone. Yes, I pay HST even though I technically don't charge clients it, but it's a small price to pay IMO to keep the gov't off my back and is offset by the small portion of wages that I don't include. He also said that many business owners try to claim silly write offs, another flag for the gov't, which is why I use his long standing, reputable services. As for not stating 100% of what I make, many business owners don't, pocketing the odd cash job here or there. Some even use it for their hobby fund because they can hide it from their SO and the gov't. Every nail salon I know doesn't charge you tax if you pay them cash and JTK has already pointed out other examples. For the record I do claim 100% of my rental property income and my other business income as well.
I feel for anyone who has been audited because I've been told by clients who have that they'll try everything to find something to nail you on because they have to justify the hours, etc. and that if you've been audited once, they'll bug you every 5 years or so, regardless of whether you were wrongfully audited in the first place or not.
As for Absalom, "judge not, lest you be judged".