In all cases I will show the benefit of time on local RE investments (even those purchased at full retail).  

Hi Flavia, Research the local market trends, economic indicators, job growth, and development plans in the area to gauge its long-term potential.

This means not only mapping the location of your existing utilities, but engaging with an experienced provider who knows how to work with your local utilities.

Hi  Nyron,I am local to the area and have a lot of connections.

If you decide to further pursue this one you need a local structural engineer who can assess the already completed fix.

Declining local economies invariably hurt home values.

Utilities, taxes (property, local vacation, & income), landscaping, furnishing / decorations / amenities, pest control, & supplies (soap, TP, etc) are the big ones on my STR calculator that you didn't mention.I'd also recommend using the enemy method to determine expected income.

Our locals will negotiate on sight distance but there has to be a reason.  

Ask local property management companies what they are seeing for utilities for similar fourplexes.I don't know the age of this building but mine are 80s built.

I recommend looking at B neighborhoods up in your local metro.