Advise with this Delay Mage?

So taking the idea from the delay mage from way back when, and adapting it to a lot of the decks I am seeing as of late.

One thing that is a bit different is that while there is a lot of wiping cards, there are a bunch combos/beefcakes. I have been having quite a bit of success with it. The one thing I like about it is that a lot of these cards are interchangeable when it comes to ze combos (ei flesheating ghoul with sorcerer's apprentice while using kill em all spells or switching the feg for the mana wyrm). This deck, I find is good for being efficient with mana, however the downside of it is if I draw high mana cost cards, I am boned if I am going against a high agro deck. I do recognize that I could definitely remedy this by throwing more lower mana cards but I am not sure where to make that change. I encourage everyone to try it if you can and give me feedback.

Sheildbearer
Arcane Explosion x2
Frostbolt
Sorcerer's Apprentice
Frost Nova x2
Ice Barrier x2
Mirror Entity
Vaporize
Flesheating Ghoul
Ironfur
Kirin Tor Mage
Cone of Cold
Fireball x2
Blizzard x2
Lord of the Arena
Sunwalker
Flamestrike x2
Stormwind Champion
AlexstraszaPyroblast