Actually, that's exactly what I've been doing. Processing the script. Anyone who would be considered as a vocal character is having their lines added into the processed script which is exactly in order as events happen, with dummied dialog filed in exactly where it would have been had Square kept it (with clear indicators showing that it's not part of the final product, of course).
Automating the process is nearly impossible because not only are the LZS archives inside of char.lgp out of order, but the text in the LZS archives themselves are often out of order as well. Plus care has to be taken to add in notes on the mood at all times so the voice actors aren't speaking completely out of atmosphere. Painfully, it must be done by hand. But I'm perfectly fine with that as long as interest remains with the project from everyone else.
My work on redoing the intro sequence has left me with rudimentary ability to restore a lot of dummied sections of the game, and I'm not saying we will, just that we're considering it. Adding in all the dummied dialogs and cutscenes makes it a lot easier to make that decision.
Note that I'm pretty familiar with the game, so I'm not dumb enough to add in something that was left out for obvious reasons. For example, certain events are referenced too early in the game in the unused dialogs. These won't be added to preserve the impact of when you learn of them for sure.