As a rogue swashbuckler, what weapons am I able to duel wield? Two Short Swords or daggers or scimitars if AL, basically any light finesse weapon duo, as long as both are light/finesse and you have proficiency in them.

Are scimitars Shortswords?

As somebody else already brought up, scimitars are almost identical to short swords aside for a smaller contact area for the pomel bash. This makes them ever so slightly better than a short sword. As far as one-handed swords go they rank as follows. Long Sword > Scimitar > Short Sword.

What weapon would a rogue use?

Rogues can use five types of melee weapons: daggers, fist weapons, one-handed maces, one-handed swords, and one-handed axes.