Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
> The protection of freedom of expression is premised upon fundamental principles and values that promote the search for and attainment of truth, participation in social and political decision-making and the opportunity for individual self-fulfillment through expression.
There is a legalistic sense of free expression/speech in various countries, yes. But it is also a philosophy and worldview that goes far beyond a legalistic sense. One that emphasizes toleration of dissent and competing views as a process to find truth, and one that recognizes the inherent importance of expression in human actualization and dignity. In that broader sense, the state/non-state distinction starts to fade away.
I think you mean tortious interference. Or maybe you were right the first time.
Those are literally the same thing. Free speech means ideas compete on their merits in a marketplace of ideas and no central authority gets to decide which ideas are worth considering. You can be against free speech --- many people are these days --- but you don't get to claim to be in favor of free speech but not this speech or that speech.