NM J&S: http://swtor.askmrrobot.com/combatlog/1ba2ee11-9dca-44ba-9c56-d42b76f9123f/overview#d=1,f=9,t=1,b=1 278 hps, 73% effective, 202 effective hps 25 force lightnings in 424 seconds, 16.3 seconds per force lightning, 91 ticks (9 missed) NM Karagga: http://swtor.askmrrobot.com/combatlog/1ba2ee11-9dca-44ba-9c56-d42b76f9123f/overview#d=3,f=33,b=2 308 hps, 81% effective, 250 effective hps 21 force lightnings in 347 seconds, 16.5 seconds per force lightning, 84 ticks (0 missed) HM Z&T: http://swtor.askmrrobot.com/combatlog/258c87c9-c05b-4f1d-8795-45693330322f/overview#d=1,f=32,t=2,b=1 283 hps, 82% effective, 233 effective hps 19 force lightnings in 319 seconds, 16.8 seconds per force lightning, 71 ticks (5 missed) HM Z&T: http://swtor.askmrrobot.com/combatlog/6ebdd830-0d5a-4c5d-a581-dc81acc99484/overview#d=1,f=13,t=1,b=1 281 hps, 82% effective, 231 effective hps 18 force lightnings in 321 seconds, 17.8 seconds per force lightning, 70 ticks (2 missed) HM F&S: http://swtor.askmrrobot.com/combatlog/6ebdd830-0d5a-4c5d-a581-dc81acc99484/overview#d=1,f=38,t=1,b=1 214 hps, 52% effective, 111 effective hps 16 force lightnings in 390 seconds, 24.3 seconds per force lightning, 63 ticks (1 missed) If you want to be conservative I would say 18 seconds per force lightning. On hard hitting fights, I would say somewhere around 200 hps as a good guess. And assuming 90% of force lightning ticks is reasonable.

If you are going to use math to argue a point it has to be correct and realistic. I don't find your math to be rigorous and your estimates of force lightning healing are not close to what is shown in combat logs. Even if a full campaign/BH assassin swaps out every high endurance armor/mod with lower endurance they will have > 22731 hp (including stim and buffs). The nerf is big - no doubt about it. Let's not exaggerate too much. There are valid points to be made about design flaws with assassins and relative weaknesses with other tanks. At the same time realise that juggs and powertechs have their own weakness relative to assassins. A very strong factor in determining the "weakest" tank is the kinds of content that is available. BioWare creates the content. They can create a boss that only makes melee attacks that can be dodged and does internal damage. An assassin on such a boss would be so much better it's not even funny. Hopefully there will never be a boss that is so unbalanced.

Generally speaking discharge and dark ward are up long enough for ~1.5 cycles of force lightning. Some bosses (Soa, Zorn, Stormcaller) can't be shielded so you don't even need to maintain dark ward. I still don't know where you are getting a 5 second force lightning from. The "false gcd" thing in annoying but can be prevented by activating off-gcd abilities while half-way through a gcd. Apparently this is being fixed in 1.3. I would say rakata geared assassins are around 25k hp with stim. Columi would probably be ~23k. I agree it's different for PvP - I didn't feel assassins were top dog in 1.2.

Thrash is not needed to keep aggro in PvE so that would be 161 - 23 = 138. But that's a bit low because you also need to maintain discharge and dark ward. You can also saber strike in there because the second shock will not be available right away. Also darkness assassins generate 10.4 force/second. So your calculation would be 138/10.4 = 13.2 seconds. I would say that the time in actual combat is a little longer than that. The heal depends on your health - PvE tanks with 26000 hp would heal for 3120 pre-nerf. I cast full force lightnings a lot in HM EC. Sometimes you need to saber strike when you could cast force lightning if something will cause cast failure in the near future. This could be needing to interrupt a cast, needing to move, needing to switch targets. Assassins are force limited so it's usually not a big deal. PvP is different. Edit: Also force lightning does not last 5 seconds.

I would disagree with giving healers (or anyone really) tranquility-like cooldowns. As soon as you do this encounters start to be designed around using them. Before you know it every fight requires 5-10 minutes of setting up cooldown rotations and writing spreadsheets/macros/etc. to get everyone on the same page. I absolutely do not want fights like Staghelm in WoW, where you have 7+ people rotating cooldowns constantly. Leave it at sniper shields (fixing the stacking if it's a problem) and that should be enough. Definitely agree with changes to how buffs/debuffs are displayed. Doesn't have to be fancy, just have an option to size the icons and filter out ones you don't want to see. The tuning in EC is quite good. I would make normal EC slightly easier to encourage people who were running normal/hard EV/KP to step into EC. Hard EC I have no complaints with the tuning. It seems the minimum DPS to beat fights is slightly higher in 8-man. I think this is a good design - it keeps 16-man guilds from downsizing to progress. I want to raid with friends and telling them to hit the road because they don't quite push out enough DPS is not something I want to do. One thing that would be very cool is a solid quest line leading into the next operation. Continuing into the operation you might need to collect special items/defeat enemies to push forward. It would be nice to have a really immersive experience. All this would be optional - if you just want to plow bosses and get loot that's fine too.