Help the newb mage.

Ok, this is my first mage and I was hoping for some advice on stats.

I mainly just PVP, and do so as frost.

I have been stacking Intellect and crit, while trying to squeeze in some haste, and ignoring Mastery. Is this correct?

Is 4% hit enough for PVP?

And last of all ; how much spell pen do I need? I read somewhere that all I need 190, is this correct?
Int>Hit to 4%>Spen to like in the 200s (just buy a necklace or the other peice that gives spen)>mastery>crit>haste.

You'll want to stack mastery for those huge shatter combos that frost mages are famous for.