we can't make pre-rooted ZVJ packages because we don't know how LG flashes the ZVJ radio firmware (without it you get no cellular service) nor do we know the signature LG uses for its official packages.
if you are starting with stock ZVJ, there are no shortcuts you can take when rooting. the guide must be followed step by step.
unless you're familiar with using a UNIX/LINUX terminal i highly recommend using the automated guide, not the manual guide. the automated guide is stickied at the top of this forum.
well actually you can avoid wiping data by downgrading to ZVH instead of ZVD, but that's the only exception in the guide, and i can't guarantee its success.