Planing a return

I'd like to see a second (maybe a third? ) scenerio split. The whens are easy, but the whats and hows are killers.

Hmm... I can think of two good spots that could be rewritten for splits.

The first is the Thamasa campaign.
If they meet Strago at the dock when they make land, they can fork into two parties with Leo and Celes (and Shadow) going into Thamasa (culminating in the burning building with Relm), while Locke and Terra (and Strago) get chased by Ultros in the mountains.  It pushes back Relm's introduction as a playable character (only becoming available right before the floating continent) but adds more non-inn development for Shadow.
The third branch could be Edgar and company back at Vector... an enemy gauntlet as they make their escape (with fewer enemies the nicer you are to the tea girl).
The only problem there is Mog... either Mog needs to become a mandatory character so that he and Cyan can have some adventures in a fourth scenario, or you'll need to be able to select party members in Edgar's branch.

The second is the World of Ruin post-Lonely isle.
Again, you have the Celes branch which plays like Vanilla through Figaro (Tzen mandatory).
For option two, you have a Locke branch starting in Maranda (with the wounded carrier pigeon), followed by a stopover in Jidoor (w/Starlet, meet up with Relm), then leading through Zozo (to get Cyan) and finally to Kohlingen.
Lastly, option three would be a Terra branch, covering the Mobliz events [w/destroyed Mobliz connecting to Cave on the Veldt and Gau], a run-in with the Zone Eater, and then a half-esper flight to Kohlingen (or a devil's road situation where the Zone Eater's 'exit' is the Coliseum... hmm, so THAT's where he gets the monsters!).
All three branches wrap up with a reunion with Setzer to go dig up the Falcon.
Of course, that kinda eats up most of the premises for side quests, so maybe that's not such a great idea.