Well I am mostly from 90's era JRPG but here I think my fave ;
best ending theme
vocalized version of World Map theme
best Intro theme
one of best battle theme
this is mostly for nostalgia, Field theme
WHAT?! but it's fun lol ! I mean that's the point of strong spell IMO. You could ease your game progression.
I guess I'm with traditional cost MP, multiply damage and add some cost MP, for TP which could regenerate, I think there should different mechanisms with AOE spell because it's easy to...