I totally agree with some of this, starting with the "your name is your bond." People hire you because they can trust you. Your reputation is your most important asset, more than your knowledge. If you're a reliable, honest, easy-to-worth with person, then clients will forgive your lack of knowledge. But if you're a brilliant jerk, then no one will hire you.

And yes, stop work if a client fails to pay. It's so tempting to say, "Well, they're nice, and if I just do xyz for them, they'll pay." No, you've found a deadbeat client. Join the club.

But there are other parts of this with which I'll disagree.

Chief among them: Contracts are important, but I see them as a formality more than anything else. If I have to sue a client, then it's all over anyway; the time and legal fees won't be worth chasing. I work with people with whom I get along and (generally) have mutual trust.

Also: I've consistently charged at the top of the market for the last few years. Some clients don't want to pay top dollar for Python training, but others do -- and the ones who do are the easiest to work with, who understand that they're spending a lot, but also getting a huge ROI.