Hi AEG
This is Kitt and I will try to answer your quetions however your physician and some wiser member than I may have the best answers for you. 
perineural invasion (PNI): PC invading the nerve sheath surrounding the nerves that enter the prostate
PIN or Prostatic Intraepithelial Neoplasia
PIN is graded from the lowest grade (Grade I) with the least changes to the highest grade (Grade III) with the most severe changes. Most medical papers categorize PIN as either high grade or low grade. High grade PIN and Grade III PIN are used synonomously. PC is associated more with high grade PIN than low grade. PIN appears to predate the appearance of PC by more than 5 years.
Neurovascular bundle biopsy
neurovascular bundles: two bundles of nerves between the prostate and the rectum that control erection. IMO I would like you to visit with your oncologist re this result too.
AEG, I do not have the answer for the impact of the 6 lymph nodes and the diease process is based on many factors.
You have the right as a patient to speak with the pathologist to have he/she explain the results to you as well as talking to your physician.
Gentle Hugs to you.