"lectures by Milton Friedman and am increasingly convinced that most state services are best left to the private sector,"
Free enterprise does lead to flourishing environments as the west and capitalism has demonstrated. Individuals succeed because they do what is economically viable, make money, but is this sustainable? State services are run by people paid for by taxes and private sector does the same thing but share holders and owners of private companies take their extra salaries out of this so something has to give,usually by paying their employees less or providing cheaper, second rate services.
Example, Britain has National health Service, paid for by taxation, is very cost effective, much more so than US private healthcare. Making money out of essential services means the people have to pay more for it one way or another, not fair.
Balanced taxes with strong emphases on social responsibility is what I get out of the Qur'an and not a free for all.