The 3 Scenarios

[Lockirby2]

Have you thought about putting encounters in the Crescent Mountain cave? It would discourage exploration (which wouldn't be great), but it would also add a little more meat to Sabin's tale. I don't recommend putting Serpent Trench enemies in there though, as making the Aspik/Anguiform Rages more accessible would give Gau some powerful stuff a little too early. Sure, you can take a trip around to the Veldt right after the Battle @ Narshe, but a lot of players won't unless they're doing a challenge run.

Also, judging by the map, it looks like Terra's group will go right after the Ultros fight. Do you plan on making that event change?