Perhaps an Engineer as a job if Musketeer is the class.

Using guns as the primary weapon.

The Tools that Edgar or any given Cid may have used could be incorporated as abilities or weapon skills?

Libra could be an ability that reveals more detailed information about the enemy (HP, MP, TP, elemental/ailment weaknesses and strengths). Else, a debuff that increases effectiveness against the target.

Drill as a melee-based weapon skill (for a ranged-based class) that deals damage, ignores defense, and/or may afflict a defense down/deprotect effect.

Maybe a type of Grenade "weapon skill" that deals AoE damage. Lore behind it may be a concoction created by alchemists using bomb ash, fire pots, bomb arms, and/or potentially explosive materials.

Just throwing it out there while we're on the topic.

edit: Forgot why I was editing. Oh well, t'will come back to me someday.