first question is what typa char u like too play if you like too use aoes as ur main source for lvling th is better i guess since sin only got 1 or 2 not sure and on the other hand ull get raped by a sin in pvp since sin has more skills for singel targets and much more powerfull skills but they are slower too lvl up with and th get the really usefull drop buff if ur using daggers th is the only job worth to switch t well a good job path for human dagger users would be
rogue-->Ruffian-->Thief-->Assasin(H)(th works too)-->blade taker(H)-->blood Stalker(H)
for elf dagger user would be
rogue-->Ruffian-->Scout(E)-->Treasure Hunter-->temple master(E)-->not sure here