And mana leak is situational.
I think they should simply remove the penalties from all boons, but raise piety costs. I mean if dracul can fully restore your hp why can't MA do the same to your mp? Magic costs 5(+4) for 1 max mp. Refreshment costs 30-40(+15) and fully restores your mp. Weakening costs 25(+5) and lowers enemy magic res by 10. Flames costs 50-60 and adds 1 fireball damage per level. Mana leak stays the same. Glyph Magnet becomes an on worship effect.