(Elric has granted me an exception to the rule about "ideas you don't intend to personally pursue".)
Concept: A mod that changes the dialogue, but leaves everything else (including cutscene gestures) unchanged. Each character will be given a very different personality and goals. However, they maintain their jobs in the story, and the dialogue exchanges still happen in the same order (Ramza, then Delita, Algus, Delita). You can think of it as a translation patch by someone who doesn't read the language.
There can be several different mods with this idea. In this topic, we will take a comedic approach, but a dramatic rewrite can also work.
Example of what could be:
Take the following personalities.
* Ramza: Zapp Brannigan. A narcissistic blowhard, oblivious to much of the world that doesn't involve him.
* Agrias: Asshole Knight. Either that strict Paladin, or a straight-up asshole.
* Gafgarion: An old man who is too tired to argue. Resigned to go with the flow.
Orbonne opening battle:
Gafgarion: "Alright, folks, let's calm down here."
Agrias: "Kill them all!"
Gafgarion: "What? Why?"
Agrias: "I'm attacking!"
Gafgarion at the river: "Ramza, let's join up with these knights helping Princess Ovelia."
Ramza: "They must've brainwashed Gafgarion!"
Gafgarion: "What?"
Ramza: "Attack!"
Process
1. Stripping all of the text from the game, playing it through, and writing down your imagined interpretations.
2. Build by committee (on the forum): Go scene by scene, deciding character personalities and then writing out lines.
3. Each character is played by a poster or posters, and they roleplay their dialogue as the game progresses.
An example of Agrias as the Asshole Knight (even if it goes beyond the "dialog only" concept of this topic):