Using 3 more points and optimizing your general outline a bit, this is what I came up with.
(some of the things you did kinda baffled me, like getting the whole ES/HP cluster at the start of the Witch tree and *not* getting Arcane Focus (18% ES), not getting Throatseeker when you're only 1 point away, stuff like that)
I took away the Resistance nodes because with a good kite shield you can easily cap your resists (if you have a bit on other gear too, and especially if you run Purity).
For gear, a high Spell Damage + Cold Damage wand will help you tremendously, a kite shield (for the all resist) is a must, in my opinion; other than that, getting 4-L Helm, Boots, and Gloves will be very helpful for Auras/Spells, the really good 5L/6L chest isn't as much a priority (and they're pretty rare, so don't build around needing one).
I would stack as much HP and ES on your gear as possible while keeping your resists high, then focus on damage-increasing stats (cast speed, elemental damage). I play Hardcore, so I always advise having a ton of survivability first, damage second.
Edit: Inner Force increases the potency of your Auras, so I think it's a good investment since you pass right by it anyway. (example: if Discipline gives you 100 ES, with Inner Force it gives you 130)
"I see now that the circumstances of one's birth are irrelevant; it is what you do with the gift of life that determines who you are." - Mewtwo