Edit the worldmap? I kinda know how I could do that, but it only displays the 3 maps in the game (for now), and a beta-test of the location maps. I started to work full-time, plus 3hrs of transport (bus and subway), which gives me not much time to continue it.

I use my editor to edit enemies, items and magic (among others (like enemy combinations and positions), but those three are the most useful)...

If you want to edit the overworld map, there is that FF4Edit program (written by Yousei, the guy who brought us the popular FF3Edit ^-^).

It takes 600KB... I found it easily a couple of years ago... It still should be.

Hope it helps...