DPSers (agi ranger, assasin) are still not as good as casters , both in PVP and PVM.
Set items are also quite useless in late game, 3 slots of teal items will be better choice. You may consider the COMBINATION of three items which requires special resources or medals. Those requirements can be met by completing special quests or mini games or defeating arch enemies in PVC. The combined item will take 1 or 2 slots instead of 3, making it more attractive to players.
Anyway, You are one of the best ORPG map makers, Robbepop
I'm downloading the new map now
( my codes are from old vers =.=')