My group got the hang of the first phase pretty well, but for some reason we always struggled really hard with the tornado phase at the end. We tried several different strategies, but always had trouble getting more than 5 people alive when he flew back to the other side at 10%. Eventually we did get a kill, but it felt very messy, and I dread doing it again next week. And unfortunately no, I don't have logs of it.
We rotated in a couple of people, but our kill group ended up being:
Tank - Monk, Paladin
Healers - Shaman, Druid
DPS - Shadow Priest, Rogue, DK, Warlock, Boomkin, Hunter
Out of the strategies we tried, we popped dual Tranquility at the start to top off the raid before going across the first time, as well as Stampeding Roar. Later we used Symbiosis on the Shaman to give the Druid the Spiritwalker's Grace so that they could move while casting Tranquility. Tornado dodging skills aside, we usually got everyone to the other side alive on the first pass.
Going back, however, the biggest problem was that damage was coming in far faster than the healers could heal, and anyone without defensive cooldowns couldn't really make it across. We couldn't get a healer successfully to the other side. We also neglected to use Stampeding Roar on the way back for some reason on our kill attempt, but it doesn't seem like that should be a requirement to have a druid for a kill, so I'm not sure what we're missing.
Any suggestions on when to use defensive cooldowns, are any particularly more important to save at a certain time? Also, how do the healers deal with healing the entire raid while on the move?