1) Recheck Your talents:
My guess Blood-Caked Blade and Crimson Scourge is Your attempt to gain threat but I haven`t got any situation where I would have problems with it. Drop it and take Lichborne + macro:
/cast [@player] Death Coil
2) Recheck Your Glyphs:
Bone Shield might be good in some situations but I prefer Anti-Magic Shell. It has saved me few times.
Strangulate is pretty useless as it costs runes which most probably will be used on BB or D-rune for Death Strike and interrupted NPC usually is not casting same spell again but running to Highest threat.
If Your are going for mastery then go for it - Red:Parry+Mastery; Yellow:Mastery; Blue:Mastery+Stamina. As far as I have been raiding there is no boss which strikes for 150k and stacking Stamina is just LK times. Yes You have Jewelcrafting but really its just not it.
Neck - Parry -> Dodge
Weapon - Gargoile is LK times. Use Swordshattering. Expertise -> Dodge/Hit
Legs - I would not touch Hit as You have only 1.2% and missing DS 3 times in a row..
Feet - Parry -> Dodge
Finger - Parry -> Dodge
Keep both Parry and Dodge as close as possible.
Expertise is a bit "overcaped" (for tank, You do not need so much) You could browse some gear, like head, where was mastery is instead of expertise etc.
Hit is a bit under which I would call comfortable. I would aim at least 3% but its on Your own. I do not have it either.
Avoidance - until Blizz will make their mind "fix" Blood Shield (like insc min heal or smth) I am "comfortable" at 30% with HoW as You not always depend on DS+Blood Shield - Example: Omnitrom Defense System where You can not hit boss while he got Barrier on and in such case You depend on healers, CD`s and avoidance.
If at first you don't succeed, you are running about average