I feel the Celes, Locke, Rachel thing was resolved at the end, from what they say before fighting Kefka, that Locke is now able to celebrate the dead and the living and Celes saying she's glad someone can accept her for who/what she is.
Then to conclude that, after the battle, Locke is able to do what he couldn't with Rachel, save her from falling to her doom. Then after saving Celes who's clinging to Locke's bandana like a security blanket, they run off hand in hand as the place falls.