i'd assume that OGCDs would be unaffected, so seraph would still be healing/shielding but succor would be an aoe dmg+debuff (damage down like bad breath perhaps? since increased damage taken on-tap would be incredibly strong) and emergency tactics would make it a bigger aoe dmg with no side-effects?
AST would become a strange one, definitely, and their sect choice could also affect their damage types (between dots and debuffs for regen/shield sects)
WHM would basically become a proper geomancer in it's own right when dpsing, had they not swapped every single skill effect to "holy but smaller" from their old earth/wind/water magics.