So far, a part of my plan is to utilize my VA loan or an FHA loan to secure my first (small) multi-family home to buy and hold here on Oahu. 

As far as real estate investing, I want to get into multi-family and apartment building real estate.

I can see a benefit from not having to re-key a property and offering the smart home system as an incentive for new tenants, has anyone thought of this for their duplexes or multi family units? 

my two cents: I prefer multis, 3 plus over singles and two families as inevitably you will have vacancy, late or missing rental income and it n my eyes is easier to swallow a piece of it than all your income or the property.Maybe down the road you could also convert to condos

However, because the first property was financed through an FHA loan, I can't use FHA as an option for financing my next property and one lender told me that any other conventional loan with a low down payment (1-3%) would not work when purchasing a multi-family property.

Multi's can be as low as 50% depending. 

Decide whether you want to offer month-to-month, 6 month, yearly or multi year leases.

Using small multi family properties (2 - 4 units) will get you there quicker.

If you want to buy a multi-unit property, many lenders will require 20% down.

We're a young family looking to buy a multi-unit (2-4) units anywhere in the triangle that is safe and ideally in a well defined neighborhood.