Everything you listed already exists in the private sector.
(Private roads, schools, hospitals, power plants, buses, and water sanitation). They do quite well for themselves.
As for crime control(such as hiring a violent army, or shoplifting), companies could form unions that will turn down the business of "convicted" criminals. If you steal from a Walmart and you get caught by their union, then Walmart and every other retailer in that union isn't going to sell to you in the future. It's against the personal interests of a company to hire their own private army.
As for crime control(such as hiring a violent army, or shoplifting), companies could form unions that will turn down the business of "convicted" criminals. If you steal from a Walmart and you get caught by their union, then Walmart and every other retailer in that union isn't going to sell to you in the future. It's against the personal interests of a company to hire their own private army.