If the problem is lobbying and corporate corruption of the government, I don't see how getting rid of the proxy and putting directly the corporations in charge will make anything better.

That's the thing, it wouldn't be corporations in charge of setting prices, there wouldn't be anyone setting the prices. Except in the case of monopolies, it would be the combined market.

It seems to me by looking around the world than when a reasonably democratic government starts providing real services to the population (universal healthcare and education, social safety net, ...) the people become less apathetic towards the government, and will get more involved with how the government is runned. It also seems to me that countries with higher wealth redistribution, like Scandinavian countries, have lower corruption.

Okay, if that's true then that's a good argument for those forms of government control. But, that doesn't argue for involving the government in the other parts of the market.

As to the third point, I'm not sure we know how to reliably make changes to the market that results in positive changes. I'd appreciate the input of an economist here, but from the basic econ I've learned, except in the cases of monopolies or other failure modes of the free market, government intervention mathematically always results in a net loss. (http://en.wikipedia.org/wiki/Deadweight_loss)