Just factoring in 5% for vacancy, repairs, and future capital expenditures, you are already at $50/door based off your anticipated rent.... and 5% doesn't leave much wiggle room when it comes to repairs/cap ex  That's only $270 each for 2 buildings, 8 total doors.   

We did interest only payments for the first year to aggressively save a reserve pile of cash for any repairs, maintenance, or capital expenditures we may need.

You probably won't have much for cap ex expenditures to start, but If one unit sits empty the other occupied unit won't even cover your mortgage.

I'm figuring I would not have to pay taxes, insurance, and capital expenditures.

Let's have a look at two examples - one in which we factor in Principal and Interest and one where we follow Dogma.Setup (Yearly Values):Income:             $12,500Principal:           $2,050Interest:             $3,800Property Tax:    $1,500Insurance:         $800Mgmt Fee:         $1,250Vac & Cred:       $2,000Cap Ex:              $500Scenario 1: NOI = (Income + Principal) - (Interest - Property Tax - Insurance - Mgmt Fee - Vac & Cred)NOI = ($14,550) - ($9,350) = $5,200Scenario 2: NOI = (Income) - (Property Tax - Insurance - Mgmt Fee - Vac & Cred)NOI = ($12,500) - ($5,550) = $6,950In both cases, Capital Expenditures is NOT included in the formula (and for good reason).

- How are you able to reduce maintenance costs, capital expenditures and move-out costs?

I analyze with 8% vacancy and you have 5% - 8 comes out to about one month of vacancy2. you have CapEx reserves at 100% and Repairs at 75% - Keep in mind that these percentage are a percentage of the monthly rent and typically wouldn't be over 10-15%Saying 100% capex and 75% repairs essentially means that every year you're going to spend 100% of your rental income on capital expenditures and 75% of your income on repairs.

Cap expenditure did not count towards "Operating Expenses".  

Not future projected cash-flow, current actuals.Remember, cash-flow is all property-generated income minus all property expenses, including taxes, maintenance, vacancy allowance, capital expenditures and, of course, debt service.

CapEx is how much you set aside for capital expenditures (say 5%) to replace major things like a roof or HVAC.