Just keep in mind that it has nothing to do with taxes and should not be mixed with the account you set up for your rental business.Think of your duplex as 2 properties: one personal and one rental.

Am I out of touch with reality to find a commercial loan on a mixed commercial/residential property, that’s 25-30 year amortization or interest rate under 4%??

Ex: families or mixed two family groups that need a smaller 3rd bedroom with a couple bunk beds for teens or young children.

I've heard mixed reactions ranging from old houses to dangerous areas.

Mixed results.

While ideally we would hang on to this property for another few years (values in this neighborhood will continue to go up due to proximity to KC downtown and commerce areas, and big mixed use developments that have begun in the area) we have had some huge opportunities land in our lap that require us to have some cash on hand, so we are looking to sell and 1031 the profits into this opportunity.

Properties with a business component of any kind - typically called mixed-use - will not qualify for the kind of loan it sounds like you have in mind. 

This way I can get started and once my savings grow an little bit I can probably mix up house hacking with BRRRR and grow my portfolio that way.

Mix use, commercial space on 1st floor locked in to lease until 2024. 900 a month, sucks a bit.

I just recently got lucky and ran into a nice off market value add mixed use.