Need Some Help

There was a discussion on Health / Shock a while ago and Hatzen08 had a solution that while not being perfect would work, see this post. You can assemble his code with xkas.

Edit: I had a closer look at all this:

Sketch command changed to "Sing" and use the Lullaby spell as its effect.

I think Hatzen08 code linked above could be used as a base to make this, it's a command that cast a spell.

Morph command changed to "Lich" and turns the person into the ghost sprite instead of Esper, same effects but also gives them undead like relic ring.

Would changing Terra's Esper sprite in FF3usME work or do you use it as well? Otherwise the esper sprite ID is maybe hardcoded in Morph code, I'd check bank $C2 and after bank $C1 (GFX related). Applying the undead status is trivial.

Possess command changed to "Scrolls" which would randomly cast Shadow's scroll items (without the actual items in inventory) in addition to Shrapnel spell.

This is again a command that cast a spell. The randomization aspect is not difficult to code.

Control command changed to "Rain" which would randomly cast Acid Rain, Flash Rain, or Heal Rain (custom) spells.

Same as above only with different spells.

I could probably do these 4 commands in a relatively short amount of time if nothing surprising arise. I'll have more free time next week but since your hack has been in development for years an extra week or two is not a long wait