The PSI Name editing screen is probably the simplest one in PK Hack, but by no means is it insignificant.  In fact, a lot of beginners come here first.

Okay, this is easy.  You can put anything in the name slots that's up to 25 letters long.  You'll probably want a space at the end, or the Greek letter at the end will get all smashed up next to the PSI name, like this:
 
•Poo used his new power, PSI Sexy Beama!

And no, I don't know how to change PSI Favorite Thing's name in this way, so don't ask.

Right next to the PSI name screen is the Teleportation screen.

From here you can change the names and targets of the PSI Teleport menu.  Until somebody decompresses the map, though, don't expect to get a whole lot of use out of the coordinate menu.  Also, it seems that the last four entries don't work in the game.  But when a ROM chucks a brick at you, build a wall with it.  You can use those spots for frequently used phrases you don't want to type out a lot, and refer to them in the text editor with the control codes [1C 06 0D], [1C 06 0E], [1C 06 0F], and [1C 06 10].