DRG:
Feint - Really only good for low level soloing FATEs
MCH:
Suppressive Fire - Good in theory but the incredibly small range (compared to Head Graze) make it difficult to use.
SCH:
Miasma II - Only ever used if being chased by a hoard of mobs and you need to kite/get away, which rarely happens/helps, because the Weight it inflicts is pretty weak.
BTW Dissipation is actually very useful.
-Adoloquium with Fey Illumination+Dissipation on a WAR using Convalescence+Defiance then Deployment Tactics can be 14k+ shield on the whole raid at the start of a fight.
-First 3minutes of Ravana EX as SCH, Cleric Stance throw on Rouse+Whispering Dawn, drop DoT's/Shadow Flare/burn Energy Drains/Broils, then when it starts charging Prelude to Liberation, use Dissipation and burn 3 more energy Drains. It will be fine because then he jumps/drops his bombs and cross fires, then does Liberation, then does the clock charges and then Warlord Shell. That's a good 1-2 minutes of not needing your Fairy, so might as well get those 3 free Aether stacks and get free DPS.