I see a couple of things on the armory but it would really help to know the situtation/group makeup. Are you talking about 5mans 10mans or 25 mans and what kind of group buffs are you getting.
If you have a lock with improved shadowbolt you can stop scorching as part of the rotation.
Disenchant that helm and have a tailor make you the hat of wintry doom ( http://wow.allakhazam.com/db/item.html?witem=41984&source=live&locale=enUS )until you get a good epic one. That alone will introduce a metagem socket and also get your hit up some. If you are running raids you need to get hit up quite a bit. The cap for the normal frostfirebolt spec is 289 if you have a shadowpriest or boomkin in the raid.
If it is a raid build you need to tweak your spec a little. You dont have Playing With Fire or Molten Fury and instead have firestarter, dragonsbreath, and blast wave. That wont hurt you as bad in 5 mans or soloing but Molten Fury is a must have for raiding frostfirebolt and Playing with fire alone will be a 3% dmg increase. Glyph of Living Bomb is very good and can replace improved scorch if you have a Imp shadowbolt lock with you. Also dont forget to finish out enchants, your cloak needs haste, your belt needs the buckle socket, you can enchant your rings, Kirin Tor rep will get you head enchant and Sons of Hodir will get you shoulder enchant. For gems i would drop everything for spellpower (and some hit) for now except to activate a meta, which would be 2 purified twilight opals.
Can probably try to help more when I find out if you are looking for max damage for 10man, 25man, or just heroic/soloing.