It's just amazing that Paladins never have gotten any of these kind of nukes that can affect all other mobs (with the soul exception of the stun knock-back nukes) since 50th level.
This one is very ideal to use from time to time if your either the Main Tank of the group or in some cases the Off Tank of the group since it dose indeed help you get a tight hold of aggro from a distance without having to stun the mobs as well, this is similar to the Paladin's Force of Disruption AA ability since it too helps the Paladin get aggro (the difference between the two is that Crush of the Crying Seas dose damage while Force of Disruption interrupts the mob's spell casting).
In fact this is something SOE should of done a long long time ago since Paladins never really had aggro nukes like this spell as it dose the exact same amount of damage as the the stun knock-back nukes and who knows they may consider releasing lesser versions of Crush of the Crying Seas if demands are strong (notice that nuke damage of Crush of the Crying Seas and Lesson of Compunction may vary depending on the rank of the spells themselves since the rank I versions of Crush of the Crying Seas and Lesson of Compunction both do 349 points of damage, rank II versions do 397 damage and the rank III versions do 429 damage).
This is by far one of the best ideas I seen happen by far, I don't know about you other Paladins reading this but I personally think it's just about time. As for the Game Description, I suggest to change it to "Channels holy power into a cohesive bolt of energy, causing 349 damage. Generates additional hate."
I don't even think this kind of spell grants extra efficacy to next two healing spells, at least I don't think since I really don't even notice it.