They are short term rentals @Marie Grabo. :) I would take some time and check AirBNB and VRBO directly and see what others are charging nightly, what their amenities are and what their calendars look like.You can compare that with the AirDNA results and get a better idea.

Does anyone know if Short Term Rental laws for landlords in Arlington County, Va are passed on to tenants?

It will be difficult but not impossible to find a lender that will take second position and very likely the first lien holder will be apprehensive to a subordination agreement..The terms will not be as favorable likely in the 7-8%'s I/O but on a new mortgage there are investors that theoretically can finance 'unlimited' units..I think with our team it's 250+ up to $100M.

At least in terms of rent, college students are paying 1100 - 1600 to rent by the room.

Also, what type of property (turnkey or fixer-upper) / and your rental strategy (short-term vs. long-term)?

I’m trying to find out how turn overs are on mid term rentals and how quickly a renter can get back in your unit. 

No matter where you choose to move, you are perfectly set up (if the money works) to house hack with your wife in one unit of a two-family and then to mid-term rent the other unit because of your medical connections.

After 2 Duplexes ($80,000), we left with $320,000 so we want to buy another 2 Duplexes (same price) with 25% down payment ($112,500/each) since we are not living there for long-term rental which left us with $95,000 left.

It had a separate kitchen and upstairs loft as would be expected, along with many other old school features, and definitely set the standard in my mind for what I enjoy in terms of style.

Quote from @Noah Bacon: Guru Programs are notoriously difficult to assess in terms of quality or outcome for their students.