i just didnt want my customers thinking we were trying to slip something past them.

I suggest setting clear goals and outlining your desires and requirements for your ideal investment property. 

Also, in general, would an appraiser likely aim to provide favorable results to keep you as a repeat customer?

Like @Alan Asriants and @Matthew Paul said location, location, location, an area during the day and night are very different things in Philadelphia.While the cashflow might be great, the greater the risk the greater the reward, but there are still plenty of other areas where you can get 200-400/month without being near the largest open air drug market on the east coast.Safe to say that enclosed area below Aramingo Ave is the better and more ideal area to consider?

I wanted to ideally use a minimum credit score cut off for tenants since that's something I'm familiar with and know how to interpret, so I'm wondering if you all do the same and if so, what screening service do you use that gives you tenants' actual credit score?

Additionally, being close to an international airport is ideal for me as I also run a small Turo business.

It wasn't ideal.

But I can't find a place to order the book anywhere in the website and don't see a way to connect a customer care.

This way you can see their work and most will have customer reviews on there as well especially if they have a Facebook page. 

Ideally 30-100 units or so.