Tools like this helped us determine that retiring in the Memphis Metro area was good for us and has helped form our investing strategy, mainly SFR and some commercial spaces (flex, studios, small office).

Financing is important but your realtor will absolutely be the determining factor whether you purchase correctly or not. 

The other main way I did it was by just telling people that I invest and kind of just talking about it all the time.

Also, factor in potential interest rate changes if the HELOC isn’t fixed.

Your accountant should be able to factor that into your total cost. 

Principal balance currently at 314kProperty Details: It's essentially a "2-in-1" property, with the main unit rented out for $1,900/month and an attached ADU bringing in an additional $1,200/month.

Taxes, costs, eviction complexity, etc are going to be a much bigger factor in your success than anything else.

The main reason I ask is because that is significantly below primary residence mortgage rates let alone any investment loans, if you can get rates like that I might need to make some changes on my end hahahTo answer your original question, assuming all else is equal long-term fixed rate debt is valuable. 

I thought there was a chance that one could use real estate to directly lower their main source of taxable income (such as a w2).

As a licensed Real Estate Broker in Maine, I managed the acquisition and renovation of 1272 Lakins Rd, Etna, leveraging my expertise and industry knowledge.