another point to Kuni, I'm sure you are a good mage, with solid knowledge, but getting crit capped is hard atm, adn you want us to be crit capped without glyphed molten armor ? Now, let me show you what is the best math atm, talent glyphs and all
http://wowtal.com/#k=48KPFb19.a8t.mage.-hDNdJ
I rule this way, and managed to get throw Magmaw, Omnotron, conclave of four winds, wyrmbreaker, Valiona, council and cho'gall without getting out of mana.
I'm not saying that your build is bad, just saying it's not perfect, others have ruled out different math getting more dps