John Thacker — Good questions. There are a whole lot of issues packed in here. Very briefly —

We need both government and civil society institutions, can’t do without either

Your argument is strong with regard to government expenditures on arts, I would leave them in private sector exclusively. Environment is different — it is matter of protecting property and public health against externalities. I don’t see the externalities in art.

Yes, some people will oppose anything — a given war, a given bridge, a given statue. That is what democracy is for. But don’t use it where it can be avoided.

As for rationale for government action for poor (although opposed by some) see https://niskanencenter.org/blog/the-free-market-welfare-state-preserving-dynamism-in-a-volatile-world/