Level 32 specs, happy so far, where to go now?Follow

I've got a human mage. I mostly solo or duo with my gf who has a warlock, and when we duo, she uses her voidwalker to tank. I started after she did, so for a period of time I was fighting much higher level mobs as she semi-PLed me. Thus, I have 2 points of Arcane Subtlety (to lower my resists against the higher level mobs).

Other than those 2 points, I've put my 21 points into fire. I have
Improved Fireball 5
Ignite 5
Flame Throwing 2
Burning Soul 2
Pyroblast 1
and also Impact 5, which helps me a great deal when I solo.

That allowed me to get, as I dinged 32, Blast Wave.

So..., now the question is where to go next. I have a feeling that doing just enough frost to get Icy Vein makes sense. That would be 11 points total, and would take me to level 43. I can see how further focus on fire might make sense, with a focus on increasing my crits and base damage {Critical Mass, Playing with Fire and Fire Power} might also make sense.

Any recs?

Note: I won't be raiding at all. This is just a casual game for me -- I am a ritred raider from EQ and if i go back to raiding, I'll do it in Norrath. I am enjoying NOT having to commit so much time to play with my little mage in WOW, but I would welcome the advice of experienced players.

Thanks much!

Andyhre