What, exactly, is “impossible?”
The lack of formal or informal power relations between members of society which some of them will not find acceptable. There simply is no such thing as ‘coercion’ simpliciter, and there is no such thing as an absence of power over other people. Human beings, like everything else, are objects and when we use them for our purposes we exploit them just as we do a mineral deposit. Whether they like it or not is their own affair, there is no objective criteria by which using people in certain ways is ‘correct’ or ‘incorrect’.
“Proactive physical coercion”
Only within a given jurisprudential structure. These are called ‘torts’. But the boundries of these are arbitrary, and reflect the interests of those who mould the legal norms; it is arbitrary to decide that minimalist propertarian norms are the ‘correct’ definition.
Freedom also has a functional definition.
No, it does not. Once again, read the Friedman article; and it woudln’t hurt to read Stirner. ‘Freedom’ is just theological rubbish; political morality is religious gibberish.
You seem to be confusing definitional arguments with ethical arguments, which is a common mistake.
No, I am saying that where political programmes and movements are concerned, there is no definitional content; it is theological squabbling over content-less words and all a disguise for the unconscious status-games that people play and then feel compelled to rationalize away.