You just need 1 point in Int and can get the rest from gear. This also has the advantage that you can use higher level Sarongs. You can cast Meteor Strike with only a single rank in Pyro, but it will be slightly more expensive to cast.

Sure you can delay your turn, but that means waiting for all enemies to finish their turn, at the risk of getting hit with a status effect in the meantime in addition to the damage that is going to be dealt to you and your team.