I was planning on only living in my unit for 1 year to fulfill my loan obligation but it has been over two years and I am still living here.

They may be fine in their comfort zone, and knock an idea when deep down they know they are not fulfilling their potential 

Also pre screen them just like a tenant but a step further have your mortgage broker look at their situation to tell you how long it will take them to fulfill the requirements to get a loan.

We would love to rent out our current primary house as a long term rental.Would we have to refinance if we fulfill that occupancy requirement?

But just about everyone will be fulfilling physiological needs such as food, sleep, and basic health.

It's very fulfilling!!

This fulfills the owner-occupied requirement while also allowing you to get your foot in the door of real estate investing.Or is your intent to purchase a single-family home and then rent it out once you PCS away from El Paso?

We know in Chicago you have to allow subleasing but we also know if a solution can be created for the tenant to be off the hook once they fulfill specific terms agreed to that they would prefer that option first and foremost and most likely be amendable to favorable terms you might have as the Landlord.  19 years later we have been able to avoid subleasing for the most part due to the higher risk of messing something up.

Another thing is that if the home has appreciated since the tenant buyer moved in (not happening in most of the country right now), they could show the purchase price vs the value and some lenders would count that equity as fulfilling the down payment requirement.

That's a great question: how do I know if someone who has a fiduciary responsibility to me is actually fulfilling it?