A shame about the extra spell sets not working out, but not much that can be done there. I guess we could extend the ROM or something eventually, but I think that's beyond us at the moment. Really as far as spells go, there's a fair amount of slots. Rydia's White contains three spells, so that can easily be made use of. Rosa and Porom do not need two sets, considering their spell learning is pretty much the same. Palom and Rydia though should probably maintain a different spell set though since Palom learns a lot of different spells earlier than Rydia. And FuSoYa's White and Black is actually quite redundant. If you give him Tellah's spells set (which by then had already been remembered) then add Nuke, White, and Quake when FuSoYa joins through event then you have FuSoYa's magic set.
So in essence there are...
Kain - Unused
Rydia - White
Porom
FuSoYa - Black
FuSoYa - White
That's five more magic sets if people wanted to give magic or skills to characters that normally don't have them.
EDIT: Oh right, almost forgot to confirm that the changes work perfectly. DarkKnight Cecil has the spells in battle and he learns spells when he levels up appropriately.