Aside from the above, have a discussion on what type of patient you'll be expecting. Reason why I brought this up was because I did work in a PP with nonpsychiatrists (counselors and a psychologist). In short, many of them weren't prepared to deal with very sick people coming into the office, being used to the type of patient that just wants someone to listen to them.
This can turn into the dung hitting the fan at the office with staff members not knowing how to deal with dangerous patients, boundary issues between staff members and patients (e.g. they thought it was alright to e-mail patients. No that is a HIPAA violation unless the patient signs a waiver allowing this), among several other problems.
Another problem was some of the providers made recommendations that were completely inappropriate but they didn't know it was because they don't have a medical background. E.g. the guy running the office, a counselor, wanted me to see patients in just about 5-10 minutes and I flat out told him no. Then I go to work and saw a bunch of people scheduled for 10 minutes despite what I told him. I threatened to leave to practice but had to go through two weeks of badly scheduled patient because they were already told to show up and IMHO it did translate into worse care.
An advantage with the model is the other providers acted as a a screen. If I was referred their patients, their patients usually weren't bad though one particular counseling didn't know WTF she was doing and often times misdiagnosed patients. I didn't want the patient to be told they had two conflicting disorders from the same office so every single time I called her up about this issue, so we could resolve this before it looked liked a split-personality office, she never called me back, making the office look like a bunch of schmucks. The problem with possibly dangerous patients was in getting brand new people whose severity of illness was highly variable.