It's not the AUA. Here are the current AUA guidelines for management of localized PC;
www.auanet.org/guidelines/clinically-localized-prostate-cancer-new-(aua/astro/suo-guideline-2017)What they say is:
7. Clinicians should recommend active surveillance as the
best available care option for
very low-risk localized prostate cancer patients. (Strong Recommendation; Evidence Level: Grade A)
8. Clinicians should recommend active surveillance as
the preferable care option for most
low-risk localized prostate cancer patients. (Moderate Recommendation; Evidence Level: Grade B)
What that means is that if you had "very low risk" PC, which means there were only two positive cores (among other requirements), active surveillance is the best option. However, those like you with more than 2 positive cores who are "low risk," AS is the preferable treatment. Some institutions hold to more stringent standards, but most agree with the AUA.
To your questions:
1. Multiparametric MRIs are only useful at finding areas suspicious for higher grade PC; i.e., GS 7-10, and are pretty useless at finding GS 6 cancer unless it is abnormally large. mpMRI-targeted biopsies are long, tedious and expensive, but if you want the extra confidence it provides to stay on AS, you can get one. Even more thorough is a template mapping "saturation" biopsy.
2. You can just ask your Uro to overnight the slides to Epstein. It's a very common thing to do. If they don't know how, here are directions (it will probably cost $250):
pathology.jhu.edu/department/services/secondopinion.cfm