To be fair its not that some skills should be removed but that they should be reworked into upgraded versions of earlier abilies adding more effects as you reach higher levels and engage stronger enemies. Ill give some examples for WHM where there should be some reworking.
To take Aquaveil as an example this should be an upgrade of stoneskin where the base Stoneskin merely adds a barrier Aquaveil adds a damage mitigation effect.
Medica should be just a strait upgrade to Medica 2. Same for Cure to Cure 2.
Aero III should be brought back and should be Upgraded to Dia 2 with higher potency.
Water should brought in at lower levels as an AoE version of Stone Eventually upgrading to Glare 2 (which is missing for some reason it skips to Glare III) at higher levels with Holy Changed to a burst damage ability after a certain amount of uses of Water. This would pace the stunlock better so mobs dont become immune so quickly.
Maybe add in Tornado/Flood/Quake as Special Burst Damage abilitys under certain requirements. It would work better than what we have now and make gameplay more engaging. It would also tie back into Conjurer at lower levels which has become increasingly disconnected from WHM at higher levels as the spells have been more or less replaced by light based spells.