Once the seller and wholesaler have entered into equitable conversion, an Assignment of Real Estate Purchase and Sale Agreement is drafted.The agreement stipulates that the new buyer will assume property ownership, which includes purchasing the home from the seller.

I doubt my relative can stipulate a lump-sum payment? 

Hey Bradley, I had to call 10 banks/mortgage lenders until I could find one that would loan me money on the stipulations that I needed. 

They tax side hustles as though you were professional but do not allow the advantage of being classified a professional when it should be able to be to your advantage (note I am not against setting qualification to be a RE professional; I am against one of those rules stipulating that it has to be your work hours greater than other jobs). 

I'm not sure of the specifics of the agreement you had with the seller, but if the contract explicitly mentioned them conveying the property either fully vacated or fully occupied, then they are in breach of that agreement and that may be the leverage you need to extend closing or terminate and submit a new offer stipulating that the eviction be completed prior to closing. 

NJ law stipulates there are 18 reasons (I'm not 100% sure on the exact number) why you can terminate/evict a tenant and you must state which reason it is when you terminate them.

In those municipalities, the onus is by no means on the customer to stipulate it in the contract, which is why I asked if anyone knew what the status is in Philadelphia.

As far as the owner paying water/sewer, this can easily be solved by passing it onto the renter and putting the stipulation in the lease that the renter is responsible for reimbursing the owner.  

Private lenders may have different stipulations like credit checks or no credit checks, prepayment or no prepayment penalty.

It stipulates in the lease agreement that they are responsible for repairs.