It is not like every dominant goes to a credentialed school and walks away with a degree and a rule book. I think it is up to the individual dominant to set rules, and it is up to the submissive to have some common sense about limits.
It was not entirely clear in your post did the guy who said he was ordered to tip send a tip or not? If he is offering a tip and then immediately revoking the offer, my experience says this guy is not a real submissive, and he needs to be put down fast. If a model was asking my opinion about it, I would coach to say something to him like "Mistress has very little time for you. Do you want mistress' attention or not?" If he disappears great. If he says yes then follow up is "You need to send mistress 100 tokens [or whatever your number is] in the next 60 seconds or I am going to silence you for the rest of today." No tip, silence him. Fast. No conversation.
I think the mistress act is some of the easiest money a model can make. The real submissive males on these cam sites are very weak-willed and very easy to please. As long as a model can train herself to give instruction and orders that are clear, most of those submissives will be very pleased and come back for more. They tend to be loyal, easy to boss around, easy to get money from, and most of their weirdness is self-directed in what they do to themselves.
To contrast, selling yourself as a model submissive is much riskier business. The viewers who want to act as dominants are often seriously demented and try to control things way outside a normal or acceptable scope. I think a model needs a lot of experience to navigate that safely. Being a model dominant does not take as much experience. You can make a lot of mistakes, and as long as your orders and instructions are clear you will usually find customers and neither side will be worse for your inexperience.
"Easy money, being a dominant Mistress?" You must be kidding me. "Easy to please... "Bahahahahahahahaha. "Loyal?" LMFAO - I guess that depends on how you define it. Self-directed (whaaaaat?). You have this part very, very wrong.
"To contrast, selling yourself as a model submissive is much riskier business. " This part I have found to be 100% true, you are correct on this part.
" The viewers who want to act as dominants are often seriously demented and try to control things way outside a normal or acceptable scope. I think a model needs a lot of experience to navigate that safely. " That is only some of them, not all. There are a proportion of them, that are truly sadistic. Many of the others just like the rewarding feeling, that comes with knowing they have the power to direct a true orgasm, or just to explore a power-play kink harmlessly. I am always wary of any who won't accept, or respect limits. Or those who feel that setting a limit, or saying "no", warrants punishment.
There are some people that do 24/7 Slave Master arrangement. That is not a paid thing tho, and there are a lot of weirdos online, who are seeking that, of women they do no know. That can be dangerous. A friend of mine actually used to talk to the BDSM Killer John Edward Robinson. He was part of her chat group on an online forum. He sent them (female forum members) pics, and all kinds of stuff, but they didn't know he was a real serial killer. Then he disappeared from the chat room for a while, and popped up on the news. She never met up with him, but he was trying to get meetups from other chicks in the same chat group. They all thought he was kinda weird, and no one would (Thank God!).
When I first started doing all this I had a completely crazy guy in Texas, try to hypnotize me, and make me agree to moving to Texas, to become his Hucow (Bahahahahaha, 100% seriously true). I did several sessions with him, then told him to F-off, when it went in that direction. Yuck. The BDSM world can be a very unsafe dark place, but there are many people who are just into it innocently, as a harmless kink also, and who are perfectly nice, sensitive, empathetic people.