New FF6 hack in discussion...thanks for any feedback.

Many maps have NPCs that have event code tied to them, so if you remove or add an NPC it can change the NPC# associated with them in the order, so you'll need to update any NPCs that are now a different # on the map. For instance Dadaluma is normally NPC #13 ($1D in actuality) on the map, so since you removed the merchant that has a # before him, it would change Dadaluma to be NPC#12 on the map... so his event would need to be updated.

Dadaluma event:

Code:

CA/96A9: 4B    Display dialogue message $042D, wait for button press
               Good day, gentle folks.
               Can I be of service?
               I hate fighting, so I'd better let you pass!
CA/96AC: B8    Set bit $1DC9($4B) [$1DD2, bit 3]
CA/96AE: 4D    Invoke battle, enemy set $45, background $3F (Default for this area), (mosaic effect enabled), (swoosh sound enabled)
CA/96B1: B2    Call subroutine $CA5EA9
CA/96B5: 42    Hide object $1D
CA/96B7: B9    Clear bit $1DC9($4B) [$1DD2, bit 3]
CA/96B9: D7    Clear event bit $1E80($34A) [$1EE9, bit 2]
CA/96BB: 96    Restore screen from fade
CA/96BC: FE    Return

Notice the hide object $1D at CA/96B5? That would need to be changed to $1C since you removed an NPC before it in order.
There are other NPCs that would need to be updated as well, for Zozo, like the dead people on the street which are handled via the map event code at CAEF85. And the jumping between buildings guy... there's a lot of NPC event stuff going on for the Zozo map.

So yeah, when removing or adding NPC to a map, be sure to check if any NPC after the # of the one you remove or add are being used by event code, and adjust their values accordingly.