I know you had a corsair in FF11 but this time I feel like an engineer type gun class would fit the mechanics and balance of this game perfectly. Engineering could be added to the game as a new craft to go along with it.

I'm not sure if they should/shouldn't have auto attacks.

They're basic rotation could grant them temporary stacks of "Deadeye" that increased crit rate by like 6% a stack. Later in the game the player could receive skills that gave them a damage bonus IF they crit, adding more variety to the different ways dps get high damage.