@Rahel Ketema - Like @John Warren mentioned you likely wouldn't have demo the whole ceiling to install ductwork typically we'd just have to build out soffits to surround the ductwork around a pre-existing wall running down the center or side of the house depending on the layout.A lot of your situation depends on the layout of your units and available space. 

Since I’m not trying to have negative cash flow, I’ll likely sell it when I leave and roll that equity into another investment property when I move to my next duty station and use a VA loan to buy another primary residence. 

I even have a neighbor kid I pay weekly to roll my trash cans down and back.  

Practice these answers until they roll off the tongue.

Find an agent wherever you are even considering, they will start sending you over properties that meet your criteria.3) I do recommend talking to a lender and getting a pre approval.

Since many buyers struggle with paying the down payment (in Denver, $1M is no longer luxury) I wonder if they'll have an extra $24K'ish to pay their buyer's agent -- I'm guessing they will want to roll it into the purchase price?

Roll Tide.

When should I get pre-approved for an upleg? 

They also tell you that you'll get Kris's personal cell phone number.. ha. yeah right. the guy legit never responds and when you call, it goes to a pre-recorded message that sounds soooo fake - its clearly not his real number and he doesn't get back to you with any valuable information.

MF has taken on that roll.. but even at that its now 200 to 300k per apartment to build new.