Protecting your income, wealth and investments requires adequately layering insurances, and it is probably worth getting an expert involved.Best of luck.

If there is no legal problem and she tours the space and finds it adequate then I would be happy to rent but I want to do my due diligence in determining if this space is acceptable to rent to more than just a single individual.

We utilize an engineering department and do a LOT of analysis to ensure our insureds are adequately protected while also pleasing our broker(s).I studied finance in college and would confidently say I'm ahead of the curve in equity investing (stocks).

So, if you can budget for maintenance and maintain adequate reserves, you will be much better off in the long run skipping purchased warranties. 

Group insurance: Look for insurers offering discounts for insuring multiple rental properties or join a local landlord association to explore group insurance options.The key is to strike a balance between cost savings and maintaining adequate coverage to protect your quadplex investment.

How does one actually perform adequate due diligence on these types of deals? 

The primary purpose is to assist eligible veterans in purchasing, building, repairing, retaining, or adapting a home for personal occupancy.Asset Protection Strategies: If your goal is to protect your assets, there are other strategies you might consider:Insurance: Obtaining adequate insurance coverage, like homeowner's insurance and umbrella policies (as @Greg Scott mentioned), can provide a layer of protection against liabilities.Homestead Exemption: Some states offer a homestead exemption that can protect a portion of your home's value from creditors.Trusts: In some cases, placing the property in a trust can provide asset protection, although this can be complex and requires legal expertise.Legal and Financial Advice: It's crucial to seek advice from legal and financial experts.

., this is also similar to co-working locations where the operator signs a master lease with the building owner and then rents out cubicles to individual customers.It takes a considerable amount of effort and money to adequately furnish a house to make it a decent STR. 

If you trust the provider and coverage is adequate - take it and run. 

You'll have to ensure it has adequate air flow with the door closed from the ductwork above and possibly the sprinkler piping which is probably dictated by building coded in your area.