I want to know what the current condition and life expectancy is of all major components and appliances is. 

My issue is I have made the mistake of financing everything out of pocket in the form of savings and two separate personal loans that have had the detrimental effect of both raising my dti and lowering my credit score by approximately 30+ points (was 700+).

There are other ways that are just as effective and not detrimental to sellers credit.

However, there is one critical component that must be present for that to work. 

But they add a component of refinance to get cash out of their rehabs to reinvest in new property. 

Being a general contractor and an experienced investor I see stuff from multiple angles and the key component of what you said was he is selling this property in the winter and that's exactly for a reason I've seen this happen many many times.

This appears to be a huge CapEx cost on top of the other major mechanical components of the house.

Those are two very key components. 

Multifamily falls out of style - Cap Rates inflate.Yes, there are baseline economic relationships, but there is a psychological component.

If this is no interest component, you need to impute interest.