The sheet can't cover everything under the sun but it can serve as a good starting point to the new investor (such as myself).

We also have a SFH investment property in Charlotte, NC with about 11 years remaining on the mortgage (the rental income covers the monthly mortgage and the taxes.)We have some cash available and we are considering purchasing an investment property in Duck, NC (where we have been going for years on family vacations.) 

Covered porch with spacious prepared area is perfect for hosting those summer backyard parties.

But I have all my tenants apply online, do my screening, do smartmove, sign lease, and pay online.

Do you cover a good portion of your rehab with cc's? 

I would be concerned about insurance not covering you if you had an unpermitted apartment in your basement that circumvented local zoning.

In my opinion this sounds like a substantial investment, and there are plenty of solid multi-family renters in the following markets:DearbornDearborn Heights Melvindale Westland& other cities immediately North, East, or West, of Detroit You're spot on about renters paying less for a duplex over a SFH but as you progress in the multi-family market you'll notice the differences aren't much if you choose the right property, construction finishes/overhead, tenant screening processes. 

Other than the normal LLC filings, you'll also have to register as a foreign entity to do business in Maryland, but other than that, I think you covered everything that I know of.

I put some of the questions I ask in this blog post:Top 10 Questions to Ask a Past Landlord When Screening Applicants

You need to be aware that your e&o insurance will not cover you when you are a party to the transaction.