Not one of the things said here are game breaking and not one of them will get your dps up. minor spec changes, enchs and so on all of that is trivial and you wont see a big change in your dmg/dps. It is something you are doing wrong, either not using right rotation/ prio system, not using keybinds , but it is your game play that is a problem for sure. Nobody cant really help you, you need to learn alone i guess.
Your dps is indeed low for your gear, on Baleroc you used pom only once on a 6 minutes fight, why? You never used any pots. You need to use all your cds, you need pots , all those things are huge dps gain. Get cooline (
http://www.wowinterface.com/download...-CoolLine.html) or some cd tracking addon, keybind everything and practice.
And for trinkets do not get Baleroc trinket it is useless for arcane mage, you dont have dots. From firelands only trinket worth getting for arcane mage is one from rag, since it scales with mastery. Other one well if you dont want to go back to tier 11 get moonwell thing.
Make some macros for your cds as well.