Hell Spikes and Deadly Disks are quite effective at level 5, and do physical damage (which can not be resisted).

For how the primary stats determine the secondary ones, see;

differences between classes (minor spoilers)
or
Early Starter Tips (NON-Spoiler Version) (contains much of the information in the above topic).


See also (spoilers)

Kaan's Mage Guide

Playing a mage character...