I was 543 ilvl for 11/13HC (and for first day of siegecrafter progression). I did have both LMG and cloak however. Finished Garrosh with 564 equipped.
I just went full haste with a few exceptions. I used stamina trinkets for Malkorok. I sacrificed expertise for mastery on Siegecrafter and Paragons.
I played around with sacrificing mastery at the start of Garrosh progression, it was superior in terms of survivabilty, but garrosh is really easy fight for tanks, so opted for expertise simply because the DPS increase it offers.
I had the luck of getting Malkorok trinket just before Paragons and Garrosh progression so I used that for both of them. I used stamina flask up until Garrosh when I started using armor and haste elixir instead.
If you are having issues, mastery gearing over expertise is viable on pretty much every boss except Malkorok. I would not do it for Thok or Spoils either. I would be careful dropping expertise below 9-10 though.
Other than that, nothing out of the ordinary really. As far as tips goes.
Immerseus - Super easy
Protectors - Super easy
Noru - Super easy
Sha - Super easy
Galakras - If you are in tower, pop all CDs on the second tower boss. Otherwise easy.
Iron Jugg - Just make sure you have CDs when you take mines
Shamans - Pop DP towards the later stacks if you are on the whatever the guy is called with stacking debuff.
General - Just have SotR for Executes, if it is in berserk stance pop a minor cooldown for good meassure.
Malkorok - Have a good CD rotation for the blood rage
Spoils - Super easy
Thok - Have a good CD rotation
Siegecrafter - Have a good CD rotation
Paragons - Let the other tank take Ka'Roz, atleast after 5 bosses died. You should take Xaril and bubble off the stacks after he dies. Kil'ruk hurts use CDs. Korven hurts use CDs.
Garrosh - Super easy
Your item level is not really that bad for your progression. If you had a cloak it would be much better however.