This is precisely the question that Richard Rorty cared most about.
I would lean towards option 6, as would Rorty if I remember correctly. After all, our views of the world our heavily influenced by the preconceptions of the society that we grow up in. The things that we view as problems in society are the things that our philosophy would likely be based on. Drawing on Nietzsche, our philosophy is our self-confession.
My English teacher plays with this idea all the time. He'll have us read books & watch movies to demonstrate how they either reflect the ideas of their time or react to other works of their time.
A massive eyeroll. 
Anyway, I think it was Alvin Plantinga who said that philosophy is the refining of our intuitions, or at least something that amounts to the same thing. A person holds many naive(with no pejorative sense) intuitions about the world that when examined carefully conflict with each other or with perceived reality. Philosophy is the disentanglement of this web into a consistent, logical and clear tapestry. View Wittgenstein and his "fight against the bewitchment of our intelligence by means of language".
This is part of why I dislike Continental philosophy. It obscures rather than illuminate, because it gets hopelessly lost in relativism and pseudo-intellectual jargon.
I don't necessarily disagree with that, though I suggest that that role would be an aid to that of social criticism, rather than its main purpose.
The caveat I would add is that the disentanglement must be of practical use to society. While streamlining one's beliefs for the sake of doing so can be a good exercise to improve mental rigor, it shouldn't become the subject of academic debates. Philosophy needs to focus on clarifying ideas that can be used to improve society (what those ideas are is open for debate & depends on one's own political philosophy). Attempting to clarify ideas that have no such value is a purely academic exercise, & one that is not as productive a use of time.
Why should it be "of value to society", whatever that is? For one who is supposed to be a libertarian, you sure seem to have a lot of collectivist ideas.
What you are proposing would basically eliminate metaphysics, and a good part of epistemology, and yet it is metaphysics that deals with the questions that have always plagued mankind.
I reject this base utilitarism, and this obsession with criticizing society; you won't find many analytical wannabe-philosopher kings. Continental philosophers, on the other hand...
