As far as SP goes, first sp into iron arrow then
max xbow mastery
6 booster(one minute duration should be good enough)
Max enhanced Basics
Max Soul Arrow
Max Final Attack(cause it's way better than it's ever been)
Max Iron Arrow(for mobbing)
Max Booster
Those are the core skills to be maxed, dump w.e you have left into w.e you want.
So at level 70, you should have
Max Mastery
Max Soul Arrow
Max Xbow Booster
Max Final Attack
Max Enhanced Basics
Max Iron Arrow