I have to agree with Corby, "as is" should still allow you to do inspections for informational purposes only.

I totally agree with Brian.  

I completely agree that starting early is key to long-term success.

Signing the lease demonstrates they agree to the terms and then you can hold them accountable.If you don't do this, then the person named on the lease and paying the rent could disappear and you would have no legal authority to charge the remaining three for unpaid rent.

@Pranav Patel, I agree with @Sofia Komrskova.

I agree w/the previous posts. 

I also do a pre-screening questionnaire over the phone before I agree to a showing.

I agree with it being a problem that was kicked down the road but if he had the discipline to fix the problem before trying to purchase another property, I wouldn’t be in this situation of trying to help him find a lender.

You already seemed to conclude you are forcing this deal, I would agree unless there's a reason why this property will appreciate significantly in the near future and the 40 year amortization schedule allows you to hold on for that to occur. 

google "all inclusive Deed of Trust" fantastic CA document we used all the way back in the early 80s If I'm not mistaken though a wrap would require the 2nd buyer to also agree to financing terms; which would be the same as me (the 1st buyer).