It is relevant because there is more to violence than merely physically harming people. Forcing people to use script money when it's not legal is a form of violence, even if they can leave town. Forcing curfew is a form of violence. Refusing to pay workers for work that isn't related directly to profit, but to workers' safety is a form of violence and endangerment, even though it's the miner that still decides he needs that job so much it's worth taking the risk.
Once you've piled up all these kinds of domination schemes, it becomes hard for the owner to actually discern the difference between all of this and physical violence ; it is also a process of dehumanization that makes it much harder to consider the workers deserve safety. Therefore, violence that goes as far as deportation, mutilation or death becomes acceptable.
My point being, there is no instance of unfettered relations of power that don't end up like that.
I believe there's a large corpus of work on the various areas involved here, if you want a specific precision, I can try to find relevant infos.
None of the things you mention are violence. The miners decided that out of all the alternatives they had, that was their best alternative. At some point they decided that it was no longer, so they went on strike. If the system had worked according to the principles I outlined then the company would not have been able to open sniper fire on the workers, and the company would have had to treat its workers better if they wanted people to come back to work.
In that set of hypotheses you laid out, you're right. My point is that observations tend to prove the predicates necessary for your model are not verified in reality.
The whole point of what I said was that in a free market the transactions have to be voluntary. Whatever your definition of voluntary, the precise meaning of which can be debated, it does not include opening sniper fire on people in order to make them work.
