Hmm. Pure INT does do more damage. MY advice would be to do what i do. Basically, dont get any skill until level 10, and keep yr skills at lvl 5. When u get to 14, lvl them up to 6, then at 15 level to 7. Keep skills at 7 and SP farm at lvl 16 until about 30K SP. then, keep 3 mastery trees maxed until lvl 32 or so, buy yr nukes (fire and lightning) and then keep a 2 or 4 lvl gap on yr skills till 42. Then SP farm again, w/e then do what u want after that.
Spear mastery tree is Heuksal.
Yr character should stay as pure INT, keep all masterys the same lvl IMO.
Stick with yr pure int, once u get nukes at lvl 30 u'll be way more powerful.
Buy GOOD farming gear, i.e all gear with str + int increase blues, try and find a good stats SOS/SOM weapon with "+1, +2, +3, +4, +5" (mine is +3) and just keep killing monsters
Its all up to you.