The problem with your spec is that it's centered around trying to be a better AOE tank. Which you won't be. You need to optimize your spec for boss tanking (because, trash is called trash for a reason, especially in this expansion) to be the best tank you can be. That's what the two specs I linked will do for you. Additionally, you don't need to stack hit or expertise, since your threat relies primarily on your rotation and the specific talents you choose. Parry, while not a bad stat by itself, is bad to gem for because it's got ridiculously higher diminishing returns than dodge, even factoring in Chill of the Throne.
"There are no men like me...only me."