Altering text via assembly without breaking things

Some text in the game isn't able to be altered by the FF3usME, though it's been an amazingly helpful tool.  I'm not much of a hacker but so far I've managed to successfully learn enough hex editting to do very simple tasks such as changing Gp in the party menu to GP (by making backup roms, searching for 86A9 and changing it to 868F until it worked instead of crashing, since I couldn't find it in the rom map) and making one event skip over a text pointer entirely (by shifting the values for animations before the text forward to overwrite it, and filling the space left before those with three instances of the "cancel animations" bit instead of one.  During gameplay it looks fine since it doesn't have any delay.)

Obviously those two solutions are probably not kosher, so before I start shortening Pearl to Holy for the text outputted by Debilitator or such how can I properly shorten text or an event without fear of messing up everything down the line?  I'm going to be sticking .ips patches from other people in later and I'm worried about stuff getting shifted by one byte or such so it crashes.