Mod Idea: FF1 rebuild of FF6

While needing a break from the hack I was working on I had an idea and I'm just wondering if some of the more experienced hackers on here would be able to tell me if this is even doable at all.

My idea is to rebuild the original Final Fantasy as a major hack for Final Fantasy VI (and yes, I already know this is a huge project that will take a long, long time and quite possibly never get finished).

The most significant problem I can foresee is creating a job system which assigns your classes. Is that even possible? Can you manipulate the event script to assign sprites and palettes to characters, and by doing so create a series of events at the beginning of the game to pick out your party of four?

And the second question is about an issue with FF6LE being incompatible with FF3usME. Is there a way around that problem, such as creating a patch of your map data changes and applying it to your ME altered data?