Well the bandit farming is famous because it's one of the places with fastest mob respawn. With a good bow you stand in one corner and just shoot the mobs, you don't have to run to find a mob they find you

It's very fast because of that very huge spawn rate.
But in theory you are able to go on a gap 9 at every level in the game. It's just that some mobs are rare, you have to run to find one, and when it's killed it takes ages to respawn.
If you passed the level 16 going to stronghold is useless because you don't get xp nor sp per kill. With your level 34 and being a chinese character I would suggest a farm around the den perhaps on yeowas (there are a couple of nice quests giving good gold), perhaps later moving to death ravine on the eyes, the mobs have a very good spawn rate.
The amount of SP and XP that you get from a kill is related to your level and the level of a monster. Red monsters give most, blue monsters nothing and if the difference between you and the mob is to great you will not even get gold drops.