If you're staying pure mage, I would go for higher defense...Range can really rip you down in f2p, as the magic armor is horrible in defensive stats. With 20 range, you can wear studded armor, something quite invaluable as you pk more and more.
I'm not a believer of no defense, and have had 40 defense on my f2p account for quite a while. It was planned, and I did get to do dragon slayer. Being able to watch as the more ignorant players say "Ew, get out of here def nub!" and "Get XXXXXX, the other kid has d hide!" is not a bad price to pay for actually having the skill. (It really is sad when you see someone your level not want to TEAM on you when you've got defense

)