Ok, first thing, as Grasen said please edit your post (should be a button at the top of your app to edit) and attach a screenshot of your UI.  Its not really there for us to criticize, its just we like to see the aspect that people play from and see if we can make any suggestions to players.  For example, we noted on a recent druid app that he had several spells missing on his bars that play a pretty important role in their rotation and he was neglecting them.

Talents - Double Time over Juggernaut.  It has better situational uses in boss encounters and you wont have a need to charge every 12 seconds during boss fights.  But there will be occasions (more often than not) where you will need to charge back-to-back.

Enraged Regeneration over Second Wind.  Kind of contradicting myself as I primarily use Second Wind, but thats because I'm too lazy to press an extra button and our healers are spot on to where I dont need it.  ER gives you a more controllable ability to use when its needed/convenient.  Say 50% and your healers are low on mana or mostly dead, ER will give you your health back quicker and faster compared to SW where you have to wait until you are below 35%, where a single boss hit can kill you.  Even after that it only heals you back up to 35%.  Its good for quest-ing/solo-ing, but the only fight that SW is truly good for, IMO, is Norushen when you are dealing with your add in the other phase and dont have healer assistance, and 1/2 the abilities in there cant be mitigated at all.

Staggering Shout confuses me, I think you're the first warrior Ive seen using it as prot.  Its more of a PvP ability.  Piercing Howl would do more for you if you are worried about add control (so long as you have aggro), and Disrupting Should would be best to help with interrupts on fights where there is a lot of crap going on and your group doesnt have reliable interrupters.

Dragon Roar/Shockwave, either/or is fine, its mostly fight specific.  I prefer Shockwave on most fights just to get that extra stun on adds (especially Galakras, General Nazgrim, Spoils, Garrosh).  Dragon Roar is great for Immerseus as you can pretty much one-shot the adds from "Split".

If you are using Bloodbath, do you have it Macro'd into your other abilities so its up on CD?  Storm Bolt, if used properly, has been having some really strong showings on single-target boss fights if you have high vengeance.  This tier is just mostly preference to the tank.  

Glyphs - Drop Victory Rush.  You should not need to be worrying about using that ability as you will likely not be killing anything during a boss fight to be able to proc VR in the first place, so the usefulness of it is very few, far and in-between, plus it burns a global CD which can be better utilized with your rotation skill-set.  Switch to Heavy Repercussions, your Shield Slam should almost always be your #1 damaging ability, and if you are utilizing Shield Block effectively, this will only help you increase your damage.  Unending Rage is still ok if you still have rage-management issues, if you can handle using only 100 rage, switch to Resonating Power to increase your Thunder Clap range and dmg to get better threat on trash and adds during boss fights, as there tends to be quite a few add situations in boss fights this tier.

Gear-wise there are a few issues.  Firstly, what kind of build are you going for?  Honestly looking at your reforging/gemming I have no idea.  You have a few items reforged to Haste.   Haste is by-far the worst stat for Protection Warriors.  You want to avoid Haste at ALL costs.  If its on an item you have, reforge it off. 

There are 3 builds you can try for, and depending on the one you want to go for, you need to go FULL reforging/gemming for it.  #1 recommended is the Riposte build.  2nd favored is Crit build.  Lastly is Mastery build.

Riposte involves the Protection Warriors new ability Riposte (introducted in 5.4) and requires HEAVY parry stacking with some dodge thrown in.  You do not want to press getting Mastery in this case.  This build gives the best overall survivability for tanks, but will also give you the occasional random spikes in dmg taken due to RNG.

Crit build involves going full out Critical Strike gems and reforging for it to boost your damage.  This spec will greatly increase the damage you take as you will lose a LOT of parry/dodge/mastery, but can help the raid end fights faster from your increased damage.  I personally would not do this build unless you have BALLER healers to keep you up.  This build is primarly there for tanks to have fun.

Mastery is generally the least preferred because it really only applies to some end-stage heroic guilds.  This involves stacking your Mastery to help smooth damage so you take it more consistently without spikes.  This will also help with 2-piece T16 and increase the healing intake from that bonus, but its not really worthwihile.  This build results in more damage taken overall than the Riposte build because while you are smoothing out spike dmg, you are not nearly as likely to parry/dodge abilities as much.

I would suggest the Riposte build as its the best honestly.  Your stat priority is Hit(7.5%)->Exp(15%)-Parry->Dodge->Mastery->Haste.

Gemming (subject to hit/expertise issues) should be

1. Red Sockets-> Parry (Red/Flashing)
2. Yellow Sockets-> Parry/Dodge (Orange/Stalwart)
3. Blue Sockets-> Parry/Stam (Purple/Defender's)

If you are low on hit/expertise, then switch out the Defender's gems for Accurate's.
You are also missing a few enchants.

1. Shield -> Parry
2. Bracers -> Dodge
3. Boots -> Pandaren Step (Mastery/Run Speed)

Reforging - There is a lot of work that needs to be done here.  Just off the top of my head, I would start out with...

1. Neck - Hit -> Parry
2. Shoulders - remove reforge
3. Cloak - Mastery->Dodge
4. Chest - Mastery->Parry
5. Gloves - Mastery->Parry
6. Belt - remove reforge
7. Legs - Mastery->Parry
8. Ring 1 - remove reforge (so only Parry is on it)
9. Weapon - Mastery->Parry
10. Shield - Mastery->Dodge

Basically what I'm trying to get you to start out at, is getting as much parry AND dodge on all your pieces as possible since those are the preferred stats.  Based on your gear with some of it being Timeless gear, etc, it makes it hard to recommend extra changes just from looking at it because the stats on timeless gear blows (not your fault).  So once you get your gems situated and get the above recommended reforging taken care of, then see where your hit/expertise is and you can adjust accordingly from that point, whether its gemming or minor reforging to get to that magical 7.5%/15%.  If you fall just under those numbers by a little bit, its not a big deal.  But if you are above them, you should be doing whatever you can to drop them as close to 7.5% hit/15% exp as you can get.  Sometimes with the gear you have, you just cant help it though.
A couple ways you can go about reforging assistance as well....
You can download the addon "ReforgeLite".  This will open up a reforge assistant window when you go to a reforger.  It will have presets set up so you just select Protection from a drop down menu and it will auto load the data to the addon.  Then you just click "calculate" and it will pop up recommendations to you for reforging.  To see those click the "show" button and it will give you all the reforge recommendations listed item-by-item. It helps a bunch, but this addon only gives you the recommendations for reforging, NOT gems/enchanting.  Whatever your gems/enchants are, the addon will calculate the reforging based off of that.
You can also utilize AskMrRobot (http://www.askmrrobot.com/wow/gear/usa/balnazzar/samjose) and select the optimize option and that can give you a direction to go.  Keep in mind though with Mr. Robot, it will try to get you to balance parry/dodge, where you actually want to stack parry.  So even using that, you will have to do a little bit of tinkering.  If you want to balance parry/dodge more, its not going to really hurt, but ideally you want to stack Parry over Dodge, even with diminishing returns.

Lastly, as Grasen said, tanking right now in Downfall is pretty full and limited.  Our 2 10-mans and 25-man raids have solid tanks, and we have a few others who are already sitting on the sidelines just in case of an emergency with no set raid spot.  If you are invited to the guild your chances to raid, as protection, would be very limited.  You would be more likely to get into a raid as a DPS, and even then, that is kind of tight right now as the 25-man has 2-3 DPS warriors almost every night.  We do have a weekly flex run on Saturdays that usually needs a tank here or there, but again, DPS is more likely.
Just to be clear I am NOT saying "No, we won't invite you to Downfall because we have too many tanks/warrior DPS".  Its more about just giving you the fair warning/understanding that raid spots are currently limited, but we will consider all applicants based on the application process and our interactions with you throughout that process.