This what I would fix.

Pacheon
-Add Berserker Arrow
-Max White Hawk Training
-Keep Mastery lvl always equal to your combat lvl (Besides lvl 100 cap won't come for another year or 2)

Fire
-Keep Mastery lvl equal to your lvl too for max damage.
-Add and Max Fire Shield Series (Always helpful, if you have 20% element reduction on jewelry and max shield, you will be totally immune for that element or imbue)
-Add and Max Fire Protection (for when fighting Int base players)
-Get rid of fire nukes (Those are for int players, besides at lvl 70 you will have only like 100 int in stats, and your nukes will be very poor, if you want to for fun then keep them at lvl 1)

Lighting
-Max phantom walk after you have Sp Farmed
-Add Concentration Series (Every Parry increase is very helpful)
You still can add another tree if you want. Ice for PvE and more defense or Heuskal for another weapon to use and +1k HP. Also you can add Force instead of Heuksal or Ice if you want to be a healer, every guild wants one. You can delevel anything else at lvl 90 besides for Fire and Pacheon which must be lvl 90.