I have a few suggestions -
1 - For example you can have that buff until character attacks, so it will not makes unfair at least to run from PK characters. I think that could make more chances against high-level player killers when you just have to run through PvP/PK zones. My thoughts.
2 - Add 10% buff for Atk Speed/MAtk Speed/Atk/MAtk/Defense activation when character join hunter zone or with Adventurer's guide. That can be triggered until character gains 20 or 40 level.
3 - Adena drop rate could be also increased with XP farm, so buying gear will not be that hard after reaching needed grade.
That's about my thoughts.