Living in one unit and renting out the other helps you scale quickly because you need a lower down payment for a primary residence. 

We’re debating whether to sell our first primary residence or keep it as a rental.

If married you can exclude $250,000 each in capital gains if your primary residence.  

Investment Info:Single-family residence buy & hold investment.

Our other rentals in completely different areas, we have a duplex in Penfield (east side suburb, our primary residence) and a duplex in the south wedge.

The easiest and straight forward option would be, as you said, to sell the current residence, payoff the HELOC (or most of it) and then get back to saving with your jobs and the rental cashflow.

A house hack for a primary residence for about two years and then you could repeat this again. 

Based on what you shared, your current residence is already a great jump start to building wealth.

People responded by explaining that residential mortgage lenders are looking for US-based customers, who have their residence, income and assets in the States.How do they view foreign debt?

Investment Info:Single-family residence fix & flip investment.