'An it harm none, do what ye will.'
We already have
proper laws like that, enforced by the police and law courts. The principle of outlawing harm is behind laws against assault, murder, drink driving and disposing of hazardous waste improperly.
Unfortunately we also have laws against possession of recreational drugs, which should be nobody's business but the user's, laws which circumscribe our right to free assembly, and laws which insist drivers have to wear a seatbelt and motorcyclists must wear a helmet because the government has decided it knows better than they do what's good for them.
I cannot support the principle of freedom of choice in everything, I'm afraid. A lot of the things we take for granted as 'culture' wouldn't be possible if everyone just did their own thing. Museums and libraries would be ransacked in short order, and the perpetrators wouldn't be hurting anybody, would they? I like the conservation of not just 'historical,' but also merely
old buildings. If I lived in a 15th century cottage, why should I not be allowed to set fire to it, or knock it down, or paint it bright green, windowpanes and all? Surely I wouldn't be doing any harm; I'd just be expressing myself. But my community would be culturally the poorer for it.
A creed that is predicated upon doing whatever you like as long as it isn't harmful would need to have a much narrower conception of what constitutes harm than we do already, seeing as the law would be very short on specifics and virtually impossible to enforce. I think the world would soon come to resemble the wasteland Max Headroom used to broadcast to.