Yes, both Mises and Hayek are definitely classical liberals. Hoppe - who is anti-state and (therefore) anti-tax - has criticized classical liberalism for its inconsistent stance on government of which the problem of taxes is a sub-species. I don’t agree with all of Hoppe’s reasons (in particular, I reject Argumentation Ethics as a sound argument) but I agree with his gist. The classical liberals made the romantic mistake of believing that the sovereign is capable of self-restraint if assisted by the intellectual class to help clearly delineate the bounds of acceptable and unacceptable government policies (of which a “constitution” is supposed to be the central core).
The problem with even one penny of taxation is the camel’s nose in the tent. Once you’ve accepted taxation as valid, in principle, then the argument is not over whether to tax or not but merely how much. Read this article by David Friedman for an explanation of how the game-theoretic concept of “Schelling points” can be applied to the economic problem of property rights. I see taxation as a universal violation of the “Schelling point” of the private property of all subjects of the Prince.
Clayton -