I was around level 40 completing the main quests for gathering the Council of Seven ...
If you die in an instand fighting the beasts in the Dark Forest it's best to first level-up more elswhere, but at level 21 it's doable, I believe.
If you increase your strength the damage of each kind of weapon go up, also the damage value of bows !
More agility = more offense & defense value & stronger bows (and other melee weapons) require more agility !
You can Always go for the passive skill "Bow Expertice" so you can shoot faster (recuperation time become shorter with this skill).
