That understanding doesn't come from the people with guns. Else the US would not need to spend $billions on guns to fight the drug trade.
I don't say the folks with guns can't do constructive things to improve trade. They can. But they don't create that understanding you're talking about.
It absolutely does. Just look anywhere in the world where there isn't a government (or "dominant gang" if you want to call it that). Trade totally breaks down. In a world where there is no entity with guns to punish use of violence, its the game theoretic advantageous behavior. Not everyone will engage in it, and most won't, but enough will to cause the framework of trade to break down.
I've traded with people who I barely shared a language with. I could probably go buy weed today if I wanted to. I've watched thousands of dollars of business transacted in situations where enforcement of the deal was in practice impossible (offshore developers). Primitive societies without governments still understand and desire trade.
Again, the understanding you're talking about doesn't come from the sovereign.
You mean that network where the operator tried to call in an hit on people? Look at how many Bitcoin networks have been hacked (the digital equivalent of using violence). And in real world black markets, (think mafia), violence is rife (even in areas where the underlying transactions aren't illegal).
That's beside the point. You stated without government the "framework of trade [will] break down". On the contrary, even after scandals and shutdown markets, new markets pop up and, incredibly, people continue to use them.
As for Bitcoin networks being hacked that is a red herring as we often hear of non-black market sites being hacked--even with the all mighty government protection.
Even with the black market, government provides a backdrop of expectations. Murderers are still prosecuted even if the murder happened in a black market trade. I'm talking about a situation where there is no disincentive to use force, e.g. a place like Somalia or rural Pakistan.
I don't say the folks with guns can't do constructive things to improve trade. They can. But they don't create that understanding you're talking about.