Ah... one detail I forgot to mention on #2.

Well, consider the following scenario. You pop a potion and Raging Strikes and apply some pretty powerful DoTs. You then bane them. Now, the mobs it spreads to do get the RS+pot buffed DoTs... but if the mobs you're spreading to have something like vulnerability down or rampart, that will weaken the DoTs even so.

As long as the mobs don't have any defensive CDs or similar, however, you don't need to worry about this detail.