Private property, financial instruments and corporations are also built on coercion. Literally, they all exist by government fiat.
You can tell yourself whatever Rothbardian fables you like, but the only real business you're building without any participation in a modern, "coercive" society is a subsistence farm.
You are correct that government currencies exist by government fiat. Who said that those had to be the only currencies? Of course government does mandate that its currencies are recognized as legal tender, but that's something that governments get away with across the board.
Corporations are indeed creatures of government. Are they required to conduct business? No, but they are awfully convenient, and allow for a lot of rotten things to occur.
Private property? If it requires government's nod, it isn't private. And, of course, we see this all the time, when government decides that it wants someone's property, and takes it. It might be your land, your automobile, or something else. It is all up for grabs.
Not sure why you're name-dropping Rothbard, but it doesn't help you here. No business is going to exist without participating in the existing society. Trade and commerce require cooperation. The alternative is what brings a society closer to subsistence farming (and it tends to leave people starving).
That's a bit of a strawman, since I said nothing about the securing of property. As you are undoubtedly aware, government does not allow a choice in this, but you're likely taking a position that it must be this way. You're also taking the rather weak stance that existing precedent doesn't allow for any other way. That kind of thinking serves governments well (they don't think well outside of the box), but not private individuals and groups.
No, I'm taking the stance that bourgeois governments are the result of a long historical process whereby the mighty displaced the weak and stole their property until there was eventually only one ruler, who enforced the property regime of their liking.
Something to that effect has undoubtedly occurred. I think that things can work differently. Do you?
We've had a chance to see a number of government experiments run their course (some continue to), ranging from absolute monarchies, to Marxist-Leninists, to Maoists, to various kinds of republics. All of them have ended up going in similar directions, over time, consolidating power, though at different speeds.
You can tell yourself whatever Rothbardian fables you like, but the only real business you're building without any participation in a modern, "coercive" society is a subsistence farm.