Definitely would like Sacred Prism back. That ability was super useful back in the day. For those that don't know what it did: AoE's next single target healing/enhancing spell. Great way to pop a Stoneskin on everyone before a fight or mid fight, AoE Esuna would be great too. However as it is currently those would be pretty much the only spells you'd pair with it. Maybe Regen too but that'd be a good chunk of enmity.
Regen is a WHM spell though so unless they changed Regen to Regen II and then swapped out Cure III for Regen it wouldn't work and then that just comes off really odd to have a job have a direct tier increase of its class ability.
Cure III as a single target heal doesn't seem like it would be very useful either unfortunately. Cure II is more than enough when big cures are needed and then there's Benediction as well.
Shroud of saints hasn't changed in function since 1.0. Sacred Prism is what you're thinking of.