Tips on playing CJR/WHM as a pseudo-DPS?

[Urthdigger]

Also don't use it if the knockback is going to burden everyone else (although if it's extremely close to a wall or does not get knocked back, you should still use it).

This is the most important thing to remember when using Fluid Aura, and it bears excluding and pointing out for emphasis. As you're likely well aware, being a healer, it is not your own singular accomplishments that are important, but the accomplishments of the group, of which you're a vital member. As such, using Fluid Aura on a target currently being attacked, while it increases your own damage, reduces the damage of any melee and the tank, and as such is ill-advised.

However, if you've learned beforehand that a monster is immune to knockback (Most, but not all, bosses are), feel free to use it then. Also, if there is an add that's not currently being attacked and is unslept (Maybe is unable to be slept, like Tonberries in WP) you can use Fluid Aura to knock it back and buy the tank 8 seconds of not being hit by it. That way you're dealing damage AND contributing to the defense.