2.) False. There are waaaaaaay too many professors, to the point where most aren't tenured and make barely livable wages. There is a limited supply of universities, but it seems like most collude on prices, or at least refuse to compete on price. At any rate, universities seem to scale pretty well to handle extremely large population bodies, aside from a few statistical outliers that don't matter for this conversation.
3.) Demand has been constant for a while, along with supply. Easy credit is the driver of price change here, not a radical shift in supply or demand.
4.) "We are trying to increase supply". Education isn't what's lacking. You can learn a lot from independent study and books. What's lacking is degree factories. MOOCs aren't degree farms, so they are not an equivalent good.