Hey guys, I saw this post and I had to create an account to answer. First, great post and thanks for putting this together.
I saw that you need more info on Lady Vashj, so I had to share.
The real challenge is in phase 2 (70%), when you must kill the Tainted Elems, drop the Tainted cores and deactivate each of the 4 generators. In the meantime, Vashj gets a bonus in her DPS based on how many regular Elems get to her.
Depending on your luck, you might have the elems pop near you. They pop at the bottom of the stairs and shoot poison at you so you can't miss them. The main issue are the adds(Coilfang Striders and Elites). The elites are to be killed fast and used to build combo points + regen, but the striders will fear you constantly (every 1.5 sec or so) while you have to get to the Tainted Elems as fast as possible. If you have 2 Striders near you, its fear lock + dead in 30 seconds.
I did 4 tries tonight with my rogue (ilvl 450) and the fucking fear got me 4 times. It just takes too long to kill the adds while you try to get to the Tainted Elems, and Vashj ends up killing you slowly. The last try I had the 4th Tainted core and was running to the generator when I died. Unbelievable. Tomorrow I'll give this another 5 tries and will update if I down her. Hope this helps