I think one great solution is housing coops. There is actually an organization that helps people start and maintain housing coops: http://coophousing.org/
Maybe, but the general acceptance process of needing to get approval by the existing neighbors seems to both be the pro & con that prevents more widespread availability of coops
Supply and competition. Vastly increasing supply would bring down prices. But of course that would eliminate the profits of property owners, so is not done.
Housing coops have a lot of potential.