I'll help
If you're going to be a cold archer, you might as well max out the Guard of Ice series for the extra physical damage reduction. So, you should probably wear garments at high levels for the magic defense too. Ice imbue is definitely a must. Frost nova is your choice, but I would do it in place of cold wave if I really had to. Crystal wall doesn't help much but you can use it to avoid KD. The ice nuke is probably not a very good choice since it's weak compared to other nukes, and you're probably going to be pure str and ranged; two more reasons not to get it. Lightning is a good sub-tree for the grass-walk and ghostwalk series, but not much else. I would recommend against fire because you should really only rely on one kind of elemental imbue.
As far as skills for Pacheon go, just get everything except for Autumn wind and you can decide between Strong Bow or Berserker. I personally favor Berserker because it's a mob attack and it hits almost twice as fast. Plus, the level 69 Devil arrow is said to be the strongest attack in the game. You can SP farm and get both, because they're both very good skills. When strong bow crits, it crits hard. In the hawk training series, max the white and blue hawks but leave the black one at a low level. Even though it does damage, the attack rating from blue hawk can probably make you do more over time.
Your main attacks will be Imbue with anti devil, arrow combo, and berserker arrow. Strong bow is a very nice starter, but don't try and use it during the fight because you can do more damage just by using two other skills instead. In PvE, archers do very well and save HP pots. In PvP, however, they depend on critical chance and tend to lose often to the other two classes unless they can pull off successive criticals in a row. That's why anti devil bow is so good. The critical ratio for anti devil is insanely high, and it stacks on top of your bow's critical. Wear protectors or garments to maximize speed and MP saving. Also, learn to use ghostwalk efficiently in PvP to escape from those mean glaviers and bladers -_- Nukers are a special case. It's pretty much luck against them as well, because while you can kill them in 1 - 3 hits, they can probably do the same to you. So, it depends on who attacks first. (Both are ranged :O)
Hope I helped! Someone correct me if I'm wrong about Cold force skills
