Precision: I absolutely have not mastered this specialisation so all points are open to debate.
Some point can be swapped:
First, you can swap 2 point from Spell Impact to Magic Absorption to increase you survivability. Indeed, Spell Impact only increases your damage done by the FrostFire bolt, it has an impact but not that huge.
Second, in the frost tree, a player raiding with retribution paladin can relocate the 1/3 point used there.
Talents which may be interesting: Magic Absorption (Arcane), Frost Warding (Frost), Frozen Core (Frost), or even Shattered Barrier (Frost) in order to maybe prevent your death when you get the aggro of an add and they come and hit you.
Major :
Frostbolt
Molten Armor
Glyph of Eternal Water
Mineurs :
Slow Fall
Arcane Brillance
*your choice*
Spam Frostbolt, if your Brain Freeze procs use Frostfire Bolt, if Fingers of Frost Proc use your Deep Freeze. Try to use your Deep Freeze as soon as you can.
Try if you can, do not use both Brain Freeze and Fingers of Frost at the same time. So use them as soon as they proc. But if you have both proc at the same time, my advice is to use Deep Freeze, then Frostbolt then FFB ! Indeed it seems that "Since the 3.3 update, the Fingers of Frost proc trigger at the end of the casting time and not when the spell hit the boss, it mean that the spell which trigger the proc already use 1 stack" [thanks to the Cybermage Website for this info] .
Wow wiki confirms that info:
"Deep Freeze:This spell now deals a large amount of damage to targets permanently immune to stuns. In addition, when this ability deals damage it will no longer consume two charges of Fingers of Frost for those mages with the Shatter talent.
Fingers of Frost: This talent now triggers immediately on casting a spell rather than being delayed until the spell strikes the target."
So if Finger of frost procs, the first stack will be consumed by the frostbolt that you just launched. And the 2nd one by your Deep Freeze you will launch instantly (without travel time) right after your next Frostbolt cast. So take care to do not use Frostfire Bolt at this time !
There are 2 smart ways to use your Cold Snap. First, if you are under nice procs and you want to make your burst longer. Or if you have 2 Fingers of Frost procs close one to each other, in order to reset your Deep Freeze cooldown.
14% (368pts) will give you 100% chance to hit a hostile NPC lvl 83 (such as bosses), thanks to the talent Precision in your build.
13% (341pts) will be enough if you have a draenei in your group (they give you 1% hit chance).
11% (289pts) will be enough if you have a Balance Druid or a Shadow Priest in your raid (they give you 3% by debuffing the target).
10% (263pts) will be enough if you have both a Balance Druid (or a Shadow Priest) and a draenei with you.
# The following points are open to discussion, I'm not enough confortable with this spec to be affirmative #
I'm not able to give you an exact score but the fact is Frostbolt has a short base casting time. So to my mind you will be able to reach the overcap. By overcap I mean the haste rating needed to cast your Frostbolt in 1 sec under Moonkin Aura + Wrath of the Air Totem + Heroism/Bloodlust + 2T10 bonus + Icy Veins. After that, work up you SP and your Crit.
Personally, I would gem myself SP oriented, same as in fire spec (with potent ametrine, or with reckless ametrine depending on my current haste).
I'll follow same rules as in the other mage specialisations.
I'll chose a list close of the Fire Spec BIS List, and if I really have a lack of haste maybe swap some items for the Arcane BIS list.
Tailoring + Engineering (the Engineer haste CD will be nice to be able to get a crit oriented gear meanwhile the gloves' CD will maintain you at 1sec cast most of time when you are not under Icy veins or others haste buffs.)