How exactly do I get Facebook to link my friends to iPhoto's Faces tags when sharing from iPhoto?

Solution 1:

I bit the bullet, and went with the following 4 Rs:

  1. Removed all faces from iPhoto who were participating in the event
  2. Removed my Facebook account
  3. Reauthenticated my account
  4. Restored (manually, one by one) the faces, making sure to use Facebook's name suggestions

And Facebook finally recognized and tagged my friends with links to their profiles correctly. Huzzah!