Precision: I absolutely have not mastered this specialisation so all points are open to debate.
The interest of this spec is to take the frost spell Cold Snap, which allows you to reset your Icy Veins and make you burst longer. To do it you will need to sacrifice your Living Bomb Spell. So it's a classical FrostFire Bolt spec without Living Bomb.
Frostfire Bolt
Molten Armor
*Your Choice* (you can for example upgrade your mana gem in order to have enough mana to take Flame Throwing talent)
Spam FrostFire Bolt and use Pyro on Hot Streak procs.
Use your Cold Snap for reset your Icy Veins during the Heroism/Bloodlust phase. (Most of time you will only benefit from 1 Cold Snap per Encounter, because the CD is very long (7 minutes) )
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 (he 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 comfortable enough with this spec to be affirmative #
In this specialisation we can named as "occasionnal" where only the constant burst on a long period matter. It seems interesting to me to maximize our critical strike, the haste should be given by the consecutive haste CDs (if it's possible play it as Troll). More over by maximizing crit chance with a Spirit Crit oriented gear will made possible to nearly reach 100% real crit via the Molten Armor buff. This way, and with proper gemming, you will maximize the damage given by the Ice Shards talent. This way you will maximize your burst damage even if you do almost nothing rest of the time.
Here I would gemming myself crit oriented:
Red sockets: Potent Ametrines (+12SP +10Crit)
Yellow sockets : Smooth King's Amber (+20Crit)
Blue sockets : Misty Eye of Zul (+10Crit +10Spirit)
In the objective to nearly reach 100% real crit
I would take a list of gear close to the Fire BIS list, but with some Items Crit Spirit oriented
Their is an example:
Head: Sanctified Bloodmage Hood (ilvl: 277)
Neck: Blood Queen's Crimson Choker (ilvl: 277h)
Shoulder: Sanctified Bloodmage Shoulderpads (ilvl: 277)
Cloak: Volde's Cloak of the Night Sky (ilvl: 264)
Chest: Ermine Coronation Robes (ilvl: 264)
Wrist: The Lady's Brittle Bracers (ilvl: 277h)
Hands: Sanctified Bloodmage Gloves (ilvl: 277)
Belt: Lingering Illness (ilvl: 277h)
Legs: Sanctified Bloodmage Leggings (ilvl: 277)
Feet: Plague Scientist's Boots (ilvl: 277h)
Ring 1: Ashen Band of Endless Destrustion (ilvl: 277)
Ring 2: Ring of Maddening Whispers (ilvl: 277h)
Trinket 1: Phylactery of the Nameless Lich (ilvl: 277h)
Trinket 2: Muradin's Spyglass(ilvl: 264h)
Weapon: Bloodsurge, Kel'Thuzad's Blade of Agony (ilvl: 284h)
Offhand: Mystifying Charm (ilvl: 258h)
Wand: Corpse-Impaling Spike (ilvl: 277h)
Hit Rating: 291/263(Alliance), 291/289(Horde)
In Theory, with this gear you will be very close to have 100% real crit, do not hesitate to change more gems in +20 crit to reach it.
I'll follow same rules as in the other mage specialisations.
Engineering + Jewelcrafting, Engineering will give you additional crit (from nitro boots) and Jewelcrafting is the profession which gives the most crit overall !