Ok I just had 1 peek at your toon before the armory went offline. Your hit is ridiculous and Heres is what I remember off the top of my head.
Yes get t10.5 chest to get t10 4pc. Than work on t10.5 helm and gatecrasher gauntlets and replace them when you can get both. This way you keep your t10 4pc and reduce some hit.
Mark of Supremacy should go ASAP, run toc 5man normal till you get Banner of Victory.
Replace ICC rep ring with agility version.
Replace the bow with Crimson Star, you will get expertise too.
.. More when armory comes back