Regarding the Locke + Moogles vs Narshe Guard event...

Yeah. I've already edited all instances of Gil called GP except the status screen, so I needed help for that. I also need to change more stuff in the status screen such as SwdTech and Blitz's names, too.

As I said in my previous post, for the menu you'll need to look for the occurrences in the C3 disassembly. You can make a search in a text file, right?

This technically is what creates Kefka's sprite, but it's labeled 1A, when in most circumstances Kefka's character ID is labeled 15. Whenever I edit it, I almost always end up getting a Soldier, regardless of what I put instead of 1A. I don't know what to do anymore. Help's appreciated.

1A is the NPC number on the map. What you'll need to to is assign Gesthal sprite ID to object 1A using event command 37. Something like 37 1A XX, where XX is the sprite ID.

Edit: Lockirby solution's work too. In fact, you could change Kefka sprite directly in FF6LE. Sometimes I tend to overlook easy solutions.