Please help me by suggesting talent changes, glyph changes, and what gear is a priority to upgrade. I have access to emblem gear, but I'm not part of a raiding guild, so raid-specific drops are unavailable.
First of all, your gemming is way off. I'm seeing hit + stam, stength and defense, and even some defense gems. Defense gems are fine if you're not capped, but try and stack stam as much as possible for reduced damage. If you need certain gems for meta which should be a purple like 10 expertise + 10 stam. Or dodge and stamina.
Also unless you're really low on threat don't get hit or expertise, and if you're tanking bosses you want to change your glyphs + talents around.
First thing I saw which is a big no no is the one point in booming voice. Never should you be concerned about your shouts since you probably will have a paladin or other warrior dps in the group with better shouts, and one point doesn't make that big of a difference.
Also like I said unless you're having major problems with threat, swap out glyph of cleave and devastate with a shield wall and last stand. Also put some points into Improved Disciplines and Shield Specialization.
Focused Rage is a useless use of 3 talent points IMO, for when tanking your generating so much rage to use things that you should never need -3 rage points per ability for offensive use.
Also, make sure that you are using CD's and trinkets wisely according to certain times you'll be taking major damage, such as Last Stand + Enraged Regeneration, or Shield Wall and a trinket. IF you do all this, I guarantee you'll be tanking like a pro.