(4) seems clearly wrong. At the most it is a parochial about the conventions for modern works (and I’m not sure it’s universally true even there). We know, for example, that “Iliad” is the title of the Iliad, but we have no way of knowing whether that title was assigned by the author or was merely conventional, and assigned after the fact. We know for a fact that “Metaphysics” (or “Meta ta phusika”) was assigned by later editors and not by Aristotle, and yet it is in fact the title of the Metaphysics.

Actually, every single one of the points, except possibly (1) (and I’m not sure about that) seems based on pretty parochial intuitions. I’m inclined to doubt that any general theory of titles is possible at all.

Lewis: “That is, a lot of people may radically diverge from the theories of their immediate predecessors on the tree.”

Brian: “Like who?”

Russell and Wittgenstein, to take a rather famous example.

Or Ramsey and Wittgenstein, if you aren’t skipping over the technicality on which Ramsey became one of Wittgenstein’s “advisors” for his “dissertation” after L.W. returned to Cambridge.