How exactly do I get Facebook to link my friends to iPhoto's Faces tags when sharing from iPhoto?
I bit the bullet, and went with the following 4 Rs:


Removed all faces from iPhoto who were participating in the event
Removed my Facebook account
Reauthenticated my account
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!