Can I take a list of Titles from a Content Type and turn them into a Taxonomy list?
Yep, it looks like I can with Node Auto Term [NAT]


  Node Auto Term or NAT is a helper module used to facilitate node-node
  relationships through the use of the Taxonomy module; i.e. when a node
  is created, a taxonomy term is also created automatically using its
  title and body in any associated vocabularies. Other nodes can now be
  tagged with terms from these vocabularies thereby establishing
  node-node relationships.