I think your Rockbiter+Frost Shock defensive lead shammy idea is pretty decent. I'm curious if L85 PvP will be effective with this setup.

I'm also curious if a nice 4xHealing Rains combo will mean that we will not have to worry too much about playing as defensively when swarmed. I typically see the waves of 5-6 people coming in advance, so I can imagine plopping down 4 rains might give us even more survivability in dealing with those situations...