I don't agree. CS, Ice Block and Ice Barrier aren't needed. No mobs should be hitting you in the first place if you're aoe farming. If, for some reason, they do, and Frost Nova is on CD, you should blink away to force leash and start over. Barrier is just a waste, assuming you even have the mana to cast it. If mobs are in melee range and Frost Nova is on CD, you've failed at aoe grinding and should reset. As for Precision, it definitely helps with the mobs, but if you're grinding mobs over your level, Frost Nova will be resisted no matter what. Stick to grinding same or lesser level mobs. One mob resisting Frost Nova is manageable anyway.
Most likely I just don't value Arcane Concentration as much since in my experience it rarely proccs often enough to skip regging while Cold Snap, Ice Block and Ice Barrier help much more in lots of situations.
Ordinary equipment "of the eagle" provides enough mana with your occasional managem to do the job and even with drinking mana and conjuring managems I usually still got to wait for respawn, not losing time while regging.
To me AC is a 10 point "do it a bit smoother, wait longer for respawn" talent most times.
One thing I don't understand is how you deal with 1-2 npcs resisting your initial Frost Nova and interrupting your Blizzard without the deeper frost talents.
This happens quite often even when fighting mobs 3 lvls below (99% hit chance).
Kiting until next Nova or running away, resetting combat, returning and herding mobs again takes more time and is more of a hassle than simply casting Ice Barrier to prevent the damage of those 1-2 while nuking the rest and drinking a bit longer after the fight.
Sure, you might use Mana Shield but why use a rather high mana cost spell to make use of a 10 point talent that saves mana?
And thats not even taking lag, npc movement (we will see both after release) into consideration, the cds might be even more usefull.
Add to that the fact that lots of farmspots are in questareas you might be forced to move on to spots closer to your lvl due to shortage of mobs (rendering aoe useless, this already happened an a low populated pve server to me) or even pvp...
I also love AC but prefer the survivability and simplicity first.