For a soloing build I'd go Immortal/Veng hybrid.

Yep, frankly I'd prefer that taunts not be the end all be all to aggro management as it is today. BTW, your forum sig isn't displaying correctly. The HTML code is being displayed rather than the image and the link to your site.

This ^^^

Yeah, everything but LI will be fine IMO.

Fair enough, Sin DPS and TPS outside of taunts is roughly equal in our testing, HOWEVER Sin damage is much more front loaded than Jug damage and so a Sin tends to grab early aggro and a Jug or PT will have a hard time getting 130% (since most of the time we're in the "ranged" threat category) of the Sin's current threat to pass him. If you focus on staying within 4 meters of the center of the boss model you only need to get to 110% of the Sin's aggro but because sustained DPS is so close its still very hard to catch up. I recommend dpsmeter.com because they do have and threat over time comparison tool which is very useful for this kind of tuning. I'd also say this kind of conversation is pretty much academic since the design in SWTOR is for tanks to use their taunts to build threat which is quite different than some other games.

The problem I have is that you're either a very poor observer as well as being a poor player or you're trolling. Lets take the first possibility, ie that you're a poor tank and lack the ability to discern how the other tank is more successful than you. 1) First none of the tanking ACs can hold aggro without using taunts to build aggro. This is true for PTs, Sins, and Jugs and their Republic analogues. If the other tank in your raiding group is holding aggro "better" than you are its MUCH more likely that he/she is doing so by intelligently using taunts than by having a significant DPS/TPS advantage. If your DPS is so bad that they can't pull threat from the tanks then you have no chance of finishing EC much less having it on farm status. The fact that you seem to be so mis-informed about how threat works IN THIS GAME lends credence to this. 2) Now, lets take the second possibility, ie you're a troll. You necro-ed a thread that hadn't been active in months on a topic that pretty much all active forum readers have figured out. You didn't provide many significant details like your rotation, your build, or (and most importantly) any combat logging. TPS is something that can tracked and compared at a myriad of log parsing sites, but the one with the best comparative threat report is here: http://www.dpsmeter.com/ Now, if you're truly serious about improving your performance then get your raid team (as they should be already) to upload their combat logs and start looking at where your threat and the Sin's threat is coming from and what the comparative levels are. I strongly suspect that your real problem is that you tanked in other games and think you should avoid using taunt to build aggro and if that is true I'm amazed that your team has been able to carry you this far.

I don't believe that anyone thinks/thought that player crafted blues/greens would have value in comparison to raid gear. Where player crafted gear does have value is for crit crafted orange since with the augment slot you can get higher numbers than raid gear.

Sonic Barrier absorbs 850 damage if you have the set bonus and 680 if you do not. Its a very useful ability but its not a 2k absorb.

Yep, I meant to come back to this thread over the weekend after I verified what you were saying and indeed you are correct. Taunting from outside of melee aggro range (not attack) does generate more threat because it works off of the threshold to pull aggro. I'll personally call that a poor mechanic but that's what's there at the moment.

Taunt and Intercede's damage resistance stack. I believe that guard does as well, but I haven't tested that explicitly.

Source? I am not aware of any serious theory crafting that demonstrates this. Certainly the work over on MMO Mechanics (sithwarrior.com) comes to a completely different conclusion.

I think a vengeance heavy build it optimal for an OT until EC. You can help the MT hold aggro by Interceding on your "hot" DPS, deal very good DPS, and when needed jump into Soresu. EC seems to require two full spec tanks though you could probably still get by in a hybrid 16/25 or similar.

All of the tank AC's require some juggling, but the one with the least is the PT.

If you run in Soresu you can kind of, but it will be slower. If you're not in Soresu then its not gonna happen IMO.

I have tanked EC and in my experience Jugs perform quite well. I outlived our Sin tank on several occasions, though we're still not certain as to why our Sin died even when we had Toth and Zorn separated. I was able to pick up both bosses and survive long enough by kiting them for our Sin to be rezzed and we resumed the fight. We did wipe on that attempt because we hit the enrage timer (6 mins IIRC) but it certainly wasn't because of Jug threat, survivabilty, or damage. Now, we can debate as to whether our Sin made a mistake or perhaps our healers were paying more attention to me than him but despite him being slightly better geared than me I never dropped nor did I have a challenged holding threat despite the multiple tank swaps and positioning challenges in the EC boss fights.