Creating An Additional Learnable Menu of Spells?

One of the major aspects of my patch involves expanding FFVI's events to tie up some loose ends. I plan to do this by adding two playable characters to the game allowing the player's to explore their narratives. I specifically plan to move Umaro and Gogo to guest slots where they can be recruited in the WoR. The new characters which we will call Character 0C and Character 0D will take their place. To accommodate the extra characters I'd like to create at least one extra command menu. Now I know how to make the out of battle skill menu option using GrayShadows' Expanded Skills Menu and point it at the Command Skill in question. I also know how to replace Relm (08) for Character 0C and how to modify the individual spells using his Natural Ability Extension hack. 

Here's what I don't know: 

1. Can I use Catone's Possess Command Menu hack to change Possess into an 8 "Spell" menu by pointing GrayShadows' Expanded Skills Menu at Possess, to make the battle menu?
   
2. If the above works, can I use GrayShadows' Natural Ability Extension Hack to add level up based learning to those "spells"?
   
3. If the above works, how do I add menu descriptions for spells that don't normally have them?
   

Here are links to the Hacks in question:

• Catone's Possess Command Menu Hack
  
• GrayShadows' Natural Ability Extension Hack
  
• GrayShadows' Expanded Skills Menu Hack