I wouldn't get any fire skills except the imbue until you can get the nuke. The extra physical damage is useless to a pure INT, and the magical damage protection...well, I don't see any use for it unless perhaps you want to PvP.
As for weapon skills I mainly use Soul Spear and Dancing Demon Spear. I'm killing Chakji right now (they are lvl 21, I'm lvl 20) and I can kill them in two hits. Imbue + Soul Spear at first, then Imbue + Dancing Demon Spear. For White Tigers I use Soul Spear + normal attack (with imbue), and that kills them.
You're lvl 24, but what level are your masteries? At lvl 19 you can get the Ghost Spear Petal, which looks pretty awesome to me.
EDIT: I hope you have Lightning? You
need to max out the Must-Piercing Force, it adds a bit more magical damage, which really helps a lot.
EDIT II: Other than that, just try to get as many items with INT bonuses as possible. You might be tempted to get items with STR bonuses for extra HP, but extra magic damage is a lot more useful. If you can get INT +1 on every item you wear or use, that's +11 to INT, which is almost three levels. That's a lot.
I want a full set of INT +3 items...INT +33 is over eight levels.
