For a purchase generally application would be to review an ID, asset statements, and LLC docs if neccesary. 

We have modified many seller financed notes over the years (with input from the servicer and a qualified attorney as mentioned by others). 

So accepting and approving multiple applicants is the norm?

Securing financing is often one of the biggest challenges new real estate investors face.

Are you not necessarily denying him based on screening criteria - Some landlords make it a requirement to view the property prior to letting the applicant apply.

So far, my experience has been good with Juan Pablo 100% financed.

Quote from @Chris Pontello: Hi Chris,Correct me if I'm wrong as I'm still learning creative financing solutions, but paying them some money would be if I could take over the loan.

Piling on...all occupants who are 18 or older (or legal emancipated minor) should absolutely be required to make application. 

It may or may not show on a credit report, depends on the servicing and you should have the loan serviced.Failure to include the debt on a future loan application is mortgage fraud, wanna go to jail?

All things being equal, I would accept these applicants, but I would require them to pay a deposit equal to two months of rent.