These right here are fully true. The entire concept is more of a loose agreement to prevent someone from attacking the other while they are sleeping or are in a restaurant in a sense. And even then it is more like the idea of you being jumped by the guys friends/group if you attacked them.
Kinda like mutual destruction in a sense. Most Thinkers and Strangers could pretty easily bypass them, those in power use them to protect themselves while planning how to strike through them, and there is actually no legal basis for them. The only thing uniting people in those rules is when their own lives, territory, and/or property is in danger. They were broken a lot and even if Taylor believed in them doesn't change the fact that she is a unreliable narrator.
Also doesn't change the fact when a 300 ton Mithril Silverback says stick to the rules or else, you stick to the rules.
(To clarify, he is considered bound by contracts. The unwritten rules is a verbal contract. Ergo, violate them and pay the price for angering the Mad Scientes)