If I went to a GC and said "Hey, take a look at this job and I will pay you" and they took the money, that is the red flag.

if it was mine here is what I would do.1. walk in to planning department in the county and check zoning and any red flags they may have.2. should be simple enough to see if it has public water and sewer then call those agencies to make sure there are no moratoriums. 

Figure a few grand to paint rooms, replace carpet in a room, deep clean and spruce the property, replace a fixture or two, etc.If you have to replace your resident annually the $9600 total income will get a gut punch.The true value of the higher-end neighborhoods is residents know if they move out of the home they have it's a challenge to find another, especially if they have been there a few years and have a competitively rewarding rent rate.All this really is is basic economics...sell ten custom widgets for $1000 or 100 standard widgets for $100 each.

In some states (usually red states), the laws are favorable for landlords. 

Now we will likely pay through another escrow agreement to a cleaning company to deep clean, so likely another 5k… but that will come out of our pockets during/after escrow.

This is a big red flag for me, I’ve asked multiple times and haven’t gotten anything back.

It was our 2nd property in that market; we have a deep bench of vendors.

When a applicant has a service dog or ESA-certified animal, is this considered a red flag? 

Though, what I have noticed, is with 1 vacancy and especially 2 I am in the red and usually have to use my nest egg to get by for 2-3 months. 

I still strongly suggest the GC--I don't know anything about Philly building codes but when I here big city, it think big red tape and your GC is going to be huge walking through the permit process.