So random thought:

Wanderer's Minuet does not make sense for BRD because BRD is supposed to be mobile. What if it was changed so that instead of granting extra damage at the cost of cast time (and no auto) it made BRD songs apply a debuff effect to enemies instead of a buff to allies and vice versa?

Just throwing ideas out but Mage's Ballad would change to debuff enemies Magic Damage output, Army's Paeon would debuff their physical damage, Foe Reqium instead of debuffing enemy magic resistance increases the rate the LB gauge fills for allies.