It is a 9 bedroom house on a third of an acre in a dense college town.

The third person is a real estate investor/realtor here in town. 

You can still collect rent from a third unit - even if the building is listed as a 2 unit. 

Thirdly, just $3,500 closing costs for a $1.8M property?

Third, my net is undoubtably higher with a management company because of their higher ADR's and it enables me to work on other things.

Celebrate the small victories reasonably.  

It's priced at a 15% cap but about a third of the mobile homes are vacant and condemned.

The city wants me to build a third staircase to the 3rd fl.

If you get a lender who tells you different ltv's, their company has overlays and you may want to get a second or third opinion.Most portfolio lenders will go to 75% cash out without regard to the number of units. 

@Khory Minor I use Tellus for my tenant screening, they cooperated with a third-party platform for tenant screening and it's totally free.