Here's my idea.
F2 Infinite HP in Battle
F3 Infinite MP in Battle
F4 Infinite Items
F5 No Random Battles
Set Exp [Select number]
Set AP for Bartz [Select number]
Set AP for Lenna [Select number]
Set AP for Galuf [Select number]
Set AP for Faris [Select number]
Set Gil [Select Number]
Set AP for different characters, because there is an achievement for getting all characters master in specific job. It's for those who don't want for others to see them cheating.