You are in the right spot to level, can go 9-14 there; i recommend investing in a Poison Wind Censer, a very awesome yet cheap 2hb weapon that simply rapes all the way up until it starts to proc (level 50 I think). Forget about using the level 5 disease dot, just use your level 9 poison dot, and throw in a frost rift (the 15 damage DD) to help you kill them.
The key part of this: Grab you a
Poison Wind Censer on the cheap...best investment you will ever make to help you level up to 50, trust me.