Just a thought I had today while playing a2 (or well - trying to):
My general observation was the same as in the latter stages of hell (without level 60 gear!). Everything that doesn't get to me is no problem at all. This works regardless of what skills you use. In fact, now please bear with me as this is just theorycrafting, I think, using Disintegrate / Archon might kill those mobs (elites, champions) that are slow, far faster and better than Blizzard / Hydra. For obvious damage reasons. You can easily pair those spells with the passive temporal flux to make the number of enemies that won't reach you even bigger. In fact, this is how I played most of act 1 inferno as well.
Now however, with whatever skillset I use, the enemies that will certainly kill me at least once are those, that are faster than I am. I mean, Jailer / Waller and the thingie that moves you towards them might just hurt you as well, but I don't fear them as much as just very, very fast mobs. That might be subjective though.
However, and I will give it a try now, an easy way to avoid faster enemies might be Slow Time. Paired with other movement impairing effects (Temporal Flux, Blizzard, whatever), you might cripple an enemies movement.
Anyone ever had any luck with it?