Excellent idea. Sounds very libertarian, very free market, and similar to what I would come up with myself.
At first I was going to ask you why the government needs to handle the roads and the other things you have under its purview. Then I realized that the "government" you talk about is really a government in name only. What you call the government is really more a business. A government is a monopoly on force within a geographic area. The vast majority of what you describe doesn't involve force (with the possible exception of "power plants would have to be inspected by scientists" -- "have to be" sounds to me like force).