@Martin Zavala this is a common problem growing landlords have.Placing your first few rental properties with the company that insures your home and auto is a great place to start off and find decent coverage at an affordable price. 

Looking to purchase a property with  an elder section 8 tenant in place at the moment. What is the best liability mitigation strategy? Do I purchase the property using an LLC or do I use an unmbrella policy? Both?

They’re pretty standard in terms of deductibles and coverages — so I’m not sure what I should be looking out for in order to choose.

The simple advice I would give as an agent, is yes, you should always have liability coverage.

I am trying to calculate my Debt Coverage Ratio.  

Because of skyrocketing costs and a shortage of qualified contractors here, there are unfortunately many who essentially can *never* go home again as their insurance coverage is not sufficient to pay the bill.

They don't mind as long as the property is going to have good cash and your DCR (Debt Coverage Ratio) is above 1.25, because they typically fund them in house. 

If it is what the seller is paying, it’s an indication of what you might be able to get, but I would not assume it’s what you’ll end up paying.A few things to check when doing due diligence on the insurance.....Cutting back the insurance coverage prior to the sale is a strategy to give assets a higher return.The seller may be able to insure the building for what they paid for it 10 years ago, say $100,000, and now you need to insure $200,000 to satisfy the bank loan.  

What has good coverage and is not overpriced for 4-unit buildings ("commercial")?

I don't know of too many commercial lenders that will accept a 28% operating budget for all expenses, they will probably run their debt-coverage test at their pro forma operating expense numbers instead.