I was thinking of offering a new lease agreement with an increase but I’m concerned they would vacate.

The home owner may have filed the BK for legitimate reasons, but as far as including the home that is currently going through a foreclosure in a trustee state is concerned, the CH 7 BK will not prevent the sale.

In fact, I was also concerned because so far it doesn't appear that the buyer's house has been relisted. 

Would you have to be concerned with any kind of laws (stalking/harassing) considering you've tried reaching out to him through various channels and are now sending someone to physically approach them (assuming there aren't a PI?

I am concerned about this, as there is obviously additional liability I would be taking on.

Of course you need to preform your own due diligence but it can be extremely valuable  to get second and third opinions.Also make sure to be very diligent in how you finance this property.

Researching this property, I found that their are two properties on the block that are in the process of being rehabbed, but there are also 4-6 other properties that are either REO or in pre-foreclosure, some, right not door to one another.My thought is that these are all properties that I can acquire at a low cost, rehab, rent, and then refinance to return the capital.Is there something I am missing, or any reason I should be concerned that there are so many REOs and foreclosures on the same block? 

I have a property in Cheltenham and the rents could be right on... or could be extremely high depending on the neighborhood.

That area is not extremely rough.

Any other concerns with adding an RDP to title of primary res?