I'd keep the BAB, but adjusting the Barrage damage and the hit die would be fine.

Everyone says BAB is undervalued and site certain classes like Wizard, Druid, Cleric, and on lower Tiers Swordsage, Bard, Beguiler, Sorcerer, Psion and Favored Soul as the reason.

But these classes aren't trying to throw out large numbers of medium damage attacks in a round as there means of combat usually, and typically have access too boosts to off set not having a full BAB progression. Since this class doesn't have those kinds of Martial Maneuvers or self boosts, a Full BAB will be improtant.