Perhaps it was at some point, but it is not complete now. That is why your damage dropped.
It’s not really a mystery. If you are only wearing 4 pieces of the set, then you are missing the 15.000% damage increase from the 6-piece bonus.
The Bug about not being able to Resurrect is completely separate from your damage issue. It is stickied at the top of the bug forums in the Player List of Known Issues Thread (#6).
You were so convinced that the game was bugged, that you abandoned your DH and created a new one from scratch and got all the way to level 60, instead of just looking at your gear to see if you did something to break your build?