Starting my very first FF6 hack and had some basic questions.

Would it be possible to lock Zaida out of the Esper menu but not Jago, but still allow her to learn spells via leveling? I want them both to be different, but equally fulfilling to grow as characters.

Absolutely! That's actually really easy, because functionality's already built into the game to lock out the Esper menu -- it's used for Gogo. And the code to learn spells via levelling is completely unrelated to learning it from espers, so there's no conflict there at all.