Changing NPC Locations

Hi guys. As part of my 3 scenarios hack, I'm looking for a way to block off Barren Falls to Sabin/Edgar/Cyan. The easiest way to do this would be to take the Chocobo merchant from Gau's Father's house and place him in front of the entrance. I've never attempted to move NPCs between maps before, and as usual Zone Doctor CE is messing everything up when I try to do it. What tips do you guys have about doing this? Note that I'm not doing any sort of expansion on the ROM, and I don't want to use the option of moving treasure/NPC data to a different bank. The point of my hack is that it changes as little as possible so that it can be used as a foundation for other hacks. Any ideas?