Originally Posted by
Sparkly
Get rid of lavawalker on boots for Precision (50 hit). Even 50 mastery is better as a mage, especially arcane. You almost never move, and when you do it's with blink.
You're about 900 haste higher than is ideal. You reforged out of 432 mastery (best stat) and into haste (worst stat by far), even though you have your t13 set to give another 500 passive haste.
Take the 3% crit effect meta gem (Burning Shadowspirit Diamon) instead on your helm.
From a brief look at the log, neither of your mana gems lined up with Arcane Power (you should stack buffs during burn phases as they scale with each other). You also forgot to use one at the end as you can fit 3 gems into a 5:30 fight (at after 15 seconds, 2:15, 4:15).
Probably more that I've missed, but familiarise yourself with the arcane compendium. It should contain most of what you need to know.