And frankly, when you open a store in a mall, it's not theft for the mall to use your rent money as it sees fit. It might build a toy train ride for kids that you disagree with, or spend on a promotion of itself. Same with a state you register your business in. We are talking about abstract entities here, but you are applying a word to equivocate with the visceral feeling one gets in a personal setting.
You could just as easily make the argument that in a near-zero inflation economy, people who are ardent savers are also thieves of economic mobility, because they keep the vast majority of money out of circulation, which stifles economic activity (making it not just a zero-sum game, but actually a negative-sum game)
I mean, you have complete freedom of speech, so you can call an apple an orange for all I care, but labeling things like inflation as theft (and generally people like you also call taxes theft) just doesn't serve your argument and betrays a complete misunderstanding of basic economics beyond supply/demand.
Issuing fiat currency is a monetary policy tool, no more no less. It can be harmful or useful depending on the context it is used.
Assigning terms with a moral imperative like "theft" to a tool is alike to assigning the word "murder" to anything that can be used as a weapon.
I didn't say "inflation was theft," I said forced inflation, with the goal of paying for something unsupported by government revenues is theft.
As to phrases anarcho-capitalists use, I have no clue.
This is too broad a notion of theft.