Now I have seen it crit in lv 3 but it wasn't a large increase.
Normal dmg was 15000 Crtical dmg was 16000
So it increased by 1000 dmg or so. My matk was 3500 and my atk was 1500. So maybe only the physical dmg side can crit I'm not sure yet. If this is correct and you're geared right with an int dex crt str build using throw weapons at level 300+ you will have 30k+ kill stick dmg. Ex.(300lv * 50) + (2500atk *3.5crt multiplier) +6000matk= 30k
Hope this answers your question.
And we still have a level 4 not released yet
On a side note throw revita seems to heal for your matk +1000.
Edit: Updated dmg formula based on helping a lv 100 alchemist. This makes more sense since dmg is based on level for other skills like blizzard and metor. This first number may be the guaranteed melee dmg vs high defense mobs.