Reed what is your mage template? I'm levelling a fire mage right now and thinking about going your same route (I don't see the point of a minimal investment in Arcane just for clearcast).
Pogo and some of the other mages might tell you otherwise, but I've tried 3 different specs all on the same types of mobs, so I can tell you without a doubt what works the best. Arcane is some toys, but clearcasting and presence of mind is overrated. Clearcasts are not predictable, and presence of mind is on such a long cooldown you'll forget about it while leveling. Arcane has some nice pvp burst options, but on matter what you'll be sitting down to drink a lot.
Ice shatter builds are lame. People will tell you ice has the best survivability, which it doesn't but shatter doesn't make up for ice's own lack in damage. So even though the spells don't cost much, you'll be taking so long to kill stuff that you're mana will end up low anyways. The shatter crits just aren't dependable.
Were I to level up another mage, I would go elementalist -- again. Of course I went elemental before the mages had their review, so I never got attached to improved arcane explosions, evocation, or clearcasts. But now that those are all trainable you get them anyways. You can live without improved counterspell just fine.
So here would be my talent build order:
overview: 20 points to shatter, 31 points into fire.
Levels 10-14: Frost Warding 2/2, Elemental Precision 3/3
Levels 15-19: Improved Frost Nova 2/2, Permafrost 3/3
Levels 20-24: Frostbite 3/3, Blizzard 2/3 -or- Coldsnap 1/1 Blizzard 1/3
Levels 25-29: Shatter 5/5
Now is where the fun begins. To kill stuff, pull with a rank 1 frostbolt, then spam it with scorch. When it gets in melee range (probably 2 or 3 scorches) frost nova and back up. Take all the time in the world and cast fireball.
Levels 30-34: Impact 5/5
Levels 35-39: Ignite 5/5
Levels 40-44:
Pyroblast 1/1, Burning Soul 2/2, Flame Throwing 2/2
Now use pyroblast after you frost nova. You'll probably kill the enemy. With burning soul you can now probably sneak in another scorch if you think you need to do more damage.
45-49: Improved Scorch 3/3, Incinerate 2/2
50-54: Blastwave 1/1, Critical Mass 3/3, Free point (I put it in master of elements)
55-60: Firepower 5/5, Combustion 1/1
Great for solo and pvp, so so much for instances, but you're usually just a drink vendor that does some AoE from time to time there anyways.