Posting a few hints/tips from official forums here, feel free to add your own...

//Twin

TIP 1

x3 Medics
x2 BH
x1 Officer
x1 Smuggler
x1 Jedi

We have two medics in the mix of it all as healing support, and leave the third to rez people as they fall. Have the jedi tank the guy just outside his little room for a few seconds to draw consistent agro, and then all others minus the rez medic attack with autoattack. When the Jedi inevitably dies, a bh needs to snipershot him to draw agro. The bh moves forward to the position, and resumes the jedi's job. If he goes down, rez, rinse, and repeat. we have the smuggler there for the cloak in case a medic goes into combat, so that we can use the noncombat rez on folks. Something that kills that rez medic is dragging burning bodies, so when you use drag, keep running so you dont land on a burning body. Our tactic is zerging the guy to keep him in play and not reset. Eventually you will burn him down if you do it long enough. I'm sure there are other tactics, but we have the same issues you are having, and this seems to be the only thing that has consistently worked for us, and by worked, i mean 3 times. I'm sure there is a better way, but it is either being hidden by the community or hasnt been discovered.

TIP 2

*Another idea I just thought of, when people are failing, is anyone in the group dual-logged? I just though about that. I often have my ent running on a second client. I don't think I had her logged on during our successful run, but she was later on the day on our two failures, perhaps with another client running some data confuses the isntance... IDk... just another stupid theory probably...

TIP 3

Phase 4: This is where alot of people are getting stuck at. I'll give a brief overview of the boss's unique abilities.

Sweeping Slash- A single target attack that hits for 40k pre-mitigation. This is triggered when the ***BOSS*** moves. The best way to counter this is have your Jedi run up to the boss and aggro him in melee range. Give him 3-10 seconds to gain aggro (depending on how confident/skilled you are), then slowly begin to DPS him. If someone pulls aggro, you're pretty much going to get sodomized.

Fire- Caused by specials. What we did is whenever someone caught fire, they ran across thebridge towards the door from the 3rd boss until it wears off, then returned to the group. The key here is to pay attention and not have ADD.

Skill damage debuff (I forget the name)- Whenever you use action, you take damage. Watch your debuffs and keep yourself healed.

The boss does perform an 18K hit, but I don't know what triggers it. We had two bounty hunters, so we just cycled dread strike and fumble to keep that damage down. The big thing here is patience. He has alot of health compared to theother bosses.

TIP 4

meds just need to SP him and he drops real quick. No elem issues, no holding back on specials. Just SP him and hit him with all you got. We only had one die during this and she only stayed down as the wall is an issue with targetting for rezzes. You may want to stand still, i know i did, no benny hill like Ax Min, but it worked a charm...Annoyingly just as it did when we first went there, and due to whatever reason we ended up taking bad advice first time he 40ked us on our second trip when the debuff wasn't used as much. GL...

TIP 5

EDITED April 12th: Established - NO FIRE a lucky bug......40k hits something you are doing wrong.

EDITED April 12th: Established - Passable in any mode....calm clenched or anger clenched (well maybe not bug mode) Stuck out /unstick and hold still dont move for 5-10 secs will put you back by EXAR temple to get back in - have also drawn agro from what I could to die and worked too...just takes longer...also one guildee said he just drove back out and back in....that didnt work for me....but /unstick so far hasnt failed.

EDITED: April 12th TIP: Phase 4 - the Clenched fist of Hate - After u have your jedi walk up and let the clenched dude attack first then beginning auto attacking for a good 10 seconds hit and then everyone starts auto attacking slowly not to draw agro...if he starts going crazy which you will notice if he's going to within the frst 5 secs..usually.....medics use Serotonin Boost on who has the Grevious Wound buff on...just worry about the one he is after at first, this person should not use specials while the debuff is on, medics do not heal until you remove first ....sometimes more then one person can have this....last a minute ...just keep the one being attacked on his feet...as long as you can. Person with agro just run across the bridge and back and repeat...just back and forth...sometimes u have to enter room but on the other side try not to go to far down to the end leave a safe zone.

ALSO use Serotonin Purge on the Clenched fist of Hate ......so keep one medic focused on char with agro with SB and heals and the other just attack and hit him with SP...yellng out who hes is on ...ON VENT or whatever you use. If needed dont stasis him...stasis your guy....

USE SPRINT RUN STIMS...HELPS A LOT....medics try and maintain one at each end of the bridge and do what you got to do there. ALSO use REACTIVE HEALS....use all you got...dont set back and try to pace through this...hoping to get lucky...just make it happen.

DO NOT HOLD OUT ON THIS GUY IF YOU DONT HAVE THE DEBUFF....AOE'S ALL OUT EVERYTHING YOU GOT...SHOW HIM YOUR HATE>>>HEHE>

Can also keep one medic out of combat and just dragging and rez...bah...but it works...just have the other or have a 3rd which some use to make sure you are applying SB and SP as much as you can.

YOU MUST MAINTAIN AGRO AT ALL TIMES!!! 100%....dont lose it or itll reset.

EDITED April 12th: My opinion: STILL THINK his reaction is related to the JEDI some how and the first attacker, maybe even the whole group. Unless some group has had him hold still without a jedi then that theory is no good...lol.

EDITED APRIL 13th: IF you are the one that catches on FIRE.....Run away from where he is....have medic SB you and again SP the BOSS as much as possible....all others need to stay in range of him or they will increase the fire spreading. And all others need to hold still as long as possible until fire starts on them....JUST run over the bridge til subsides but make sure medic throws a serotonin boost your way. The fire is easily avoidable but can creep up on you so pay attention to your buff bar...grevious wound bad..hehe..no attack specials while GW is on you....try to reactive heals and stims more then regular heal.

STAY IN RANGE OF HIM.....IF have a pistol 35m or less......etc.....make sure you can target him and fire on him or the FIRE will increase on or around those out of range.

In phase 4, all cept Jedi (who tanks the boss as usual) stand on the left side of the boss in the small room and /kneel. Stand perfectly still (/kneel makes that easier) and use everything you got on the boss. If someone should get on fire anyway, he/she runs on the right side of the boss, across the bridge and back, to get rid of fire.
Medics spam heals, in case the Jedi gets a 15k hit he needs 100% health all the time.

Just so you know though, if this is reffering to making the boss "stand still" and having him minimize his dmg output - its a bug.

And last thing i heard was its getting a fix. If so it wont last long...there must be another trick to it.

//Twin