This is badly wrong
1) BRD LB does not depend on your stats. In fact, healer LB restores a fixed % of HP at tier 1, tier 2 (30 and 70% respectively iirc) and fully heals (+raise) at tier 3
2) songs are not affected by your mind. They give a fixed % of MP/TP
3) piety does so little to your mana pool when you're not a mage that it would be pointless to rely on that to increase song's effectiveness.