So what game would you base the initial skeleton off of? Will you be aiming for it to be able to duplicate the full range of NES-SNES games? I would say any of the games from 3 (NES) to 6 would be a good place to start.. but the original game would be great, too. It definitely needs to take a different approach than RPG Maker does, with more of a focus on duplicating things about FF that people like.