Also besides residential there is commercial and industrial lands and a host of zoning issues.Each aspect and real estate type has maybe similar, but largely different skill set requirements. 

Zoning and Land Use: Check with local zoning authorities to verify the property's zoning classification and ensure it aligns with your intended use.

Try to get most of your learning out of the way before you try to do a transaction.Buyer seller agent    Commission splitNo subject to financingZoningMarket 3/2 2/1 parking school districts addl ADU property taxes insurance flood zones etc etc.  

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

Also the land in question already has a well and septic system with electricity on site as well as a driveway and is zoned for cabins/mobile homes and single family dwellings among a few other things.

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. 

But of course that requires approval of some signage committee somewhere, or must comply with local signage laws and zoning laws.

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

I know it's not mortgages - I've heard a lot of horror stories about processing done in one time zone, underwriting done 1,000 miles away and appraisal reviews being done in a 3rd time zone and none of them knowing what is going on with eachother.

I would avoid the flood zone.