Equipping Skills For Battle

so for my game I have a very FF9 style class system: characters can swap between classes, learning skills for each class. during battle (and through the main menu) they can only access the skills that are for that class (the princess has access to the "prayer" skills as a healer, and "vanquish" as a war priestess, etc etc), which is kind of a pain in battle, as all those other great skills you've learned are unable to be used.

soooo I'd really like to implement a system whereby in the "skills" menu, it shows first the list of skills that are currently usable by the character (does this by default, check!), and then has a list of all the other skills that the character has learned, but can't use.

then I'd like the player to be able to navigate through that list, and "equip" up to three (maybe five? I'd love this to be changeable, so I can find a nice balance) skills; possibly the unequipped skills are grayed out, or the equipped skills have a little icon next to them, either could work. it would be great if all those skills were usable from that menu, too (so you don't have to change your character's class just to access the heal spell while out of battle. limitations on skill use are usually stupid when you're just walking around), but that's not too important. also you'd obviously be able to unequip the skills in that list too.

in battle, there'd be an extra command "Equipped Skills", or something similar, that leads to a little list of those (up to)three skills, and you'd be able to use them, even though they're not typically usable by your class.

is this at all possible? I feel like it would add a strategy element to my game, and also makes those previous skills feel less worthless (already in my game it is pretty troublesome when you run out of antidotes and you have to shuffle classes around just to get at a nice status ailment-clearing spell)