First of all sort out your talents in my opinion: take improved leader of the pack, and infected wounds.
You can change these on cost of mangle CD reduction (it's damage is going to be reduced anyway) and reduce some rend and tear in my opinion. Druid tanks do quite a damage these days anyway with gear changes/glyphs and all-loved swipe.
If you do not dps in cat form alot, also I would advice to take off primary furry - why would you want 5 rage on every crit you get if you have reduced chance to be crited by atacker anyway? You wouldn't see me around in cat form unless I'm running so I do not bother to have that talent.
I think there is never enough of stamina for druids - thats what we are proud off! Say: wait untill you see me in bear form... but if your armor lets you down, stamina goes like puff!!
So, I would advice to get more armor - simple - get a new staff
from heroic UK last boss, (maybe you have it and it just doesn't show on armory?). I'm ashamed to say I couldnt tell exact percent or my armor unbuffed... but I still hope to get more. (comparing amories I nearly have 1 k more in caster form...)
I think only dodge gems are pretty limited, and better go with agility(little armor/dodge and crit for damage! ). Too bad you have to make a compromise on agility and expertise cose they are both red gems and gear offers red/yellow slots usually and orange slots suck bad for tanking in my opinion, (please correct me if im wrong).
Also, gems need a review with every item you change - one day you think you would do anything for more expertise, next day you get and item and rating is fixed!
So getting Gems is ongoing daily quest I think.