If you are not using your CDs because you don't need them you're simply not playing the job to its fullest. DPS classes don't "need" their CDs to kill things, but they use them anyways since they kill things faster. Taking the same mentality, even if you don't "need" the CDs to survive, you still take less damage anyways.

Using CDs will depend on what you're pulling, how you're pulling it, and what you're fighting.

The basic rule is: The bigger the damage you're about to take, the bigger the CD you use.

If you pull from the start of SMA all the way 'till a wall stops you, it is advised you chain Hallowed Ground and as son as it drops you use Sentinel then Rampart. After those CDs are down the damage income should have slowed down enough for you to not need any more CDs.

Also using CDs is a good way to stay out of the tank stance. Rampart makes it as if you're in Shield Oath while you are in Sword Oath, Sentinel is more effective HP than ShO.