The best opportunity you will have to replacing out-dated systems (plumbing, electrical, HVAC) and improve the energy efficiency of the building envelope (air sealing, insulation, fenestration) is before a building is placed into service.  

id say for sure new paint, new countertops, new stove/fridge, new front door & just a few windows need to be replaced. i drove around the property and some of them have already been replaced. 

You should still hire engineer (~$500) to evaluate and estimate cost/time frame to fix. 

With a Tenants (aka Renters) policy, they would pay the deductible ($100, $250, $500, ... depends on what they select) and then the Insurance company pays the cost to replace the items up to the policy limit.2.

Found a structural engineer!

My goal is replacing my income over time and it takes time to do that. 

Also, when it comes to replacing things...it may cost a bit more money upfront, but if you put in quality material/appliances (within reason), they are likely to last longer. 

biggest unseen expenses I can anticipate might be floor joists, electrical, plumbing (it's got public sewer and water), and perhaps just general full cosmetic replacement if the tenant moves out.

What I can offer to you: I have problem-solving and financial skills: I have an engineering degree and an MBA in finance.I have 12 years’ experience in Procurement for Fortune 100 companies, covering the range from tactical purchasing through complex contract negotiation for all kinds of goods and services.I can help to find deals: You probably have an established process to scour for deals but need someone with the time to do it.

Though they advertise primarily as an engineering firm for new construction, they do foundation repair work-- I just called them to confirm :)