I agree that it needs a rework, but never get rid of it.
I like the idea of making it a WHM only skill. It could be done if ad a def bonus for Light Party and Full Party formations along with some buffs to AST and SCH skills:
WHM could get Protect as an aoe 20% damage reduction buff with an animation similar to the ones used by Louisoix or Kan-E-Senna on the ARR openig movie.
SCH could get a 10% damage reduction on Adlo (This would justify increased mp cost when compared to Whm and Ast equivalent skills), 5% on Succor (both effective only while the shield part is up) and a buff to Sacred Soil effect.
AST would get duration increase on The Bole (maybe with a buff on its effect too as form to compensate its RNG nature) along with a buff to the damage reduction % of Collective Unconscious and a 5% damage debuff effect to Gravity.
I think this would give a more unique feel to the gameplay of these classes :)
