How are you measuring your TPS? Via Omen? If so, then that's not very accurate. Get a WWS report and post it here. In any event, 700-800 TPS is fine given your gear but it really depends on whether you are just generating threat or also debuffing (tc, demo).
Yes, hard to give you an accurate assessment since the eagle phase skews your numbers.
1. The number of revenges seems low compared to shield slam.
2. Looks like you might have thunderclapped too much. 22 hits (11 minutes worth) in a 9 minute fight where you don't need TC up during eagle phase.
3. The number of heroic strikes seems low. I think might do 80-90 on Zul'Jin and that's with doing almost nothing on the eagle phase except re-fresh devastate.
4. Use Beserker Rage. It will fill up your rage. Just make sure you use when the time is right - rage bar low, shield block up and topped off on health. You can use it at the start of the battle for sure without any danger. Use a macro that switches you to Beserker Stance, activates Beserker Rage and switches you back to Defensive Stance.
5. I'm suprised you rage bar got empty though since you have windfury although it only went off 9 times. That seems low.
6. You might try altering your talent spec so its more of the threat build. Drop imp taunt either way. If you want more threat, drop imp defensive stance as well and get anger management and imp heroic strike.
7. Thendrius should be keeping insect swarm up for you.
It's important to keep in mind that Threat, even moreso than DPS, is very fight dependent. Just because you can put out 1300 TPS on one boss, doesn't mean you're going to generate that (or even anything near it) on every boss you come across.
So many factors contribute to your ability to generate threat on a fight that it's impossible to say whether that 700 TPS is indicative of a problem, or just typical of a Tank at your gear level on that particular fight. In other words, don't assume that because your threat is inconsistent that there's a "problem."