. $5400 comes with too much risk and wear and tear on the property. 

@Marc Zak Using an LLC for each property provides strong liability protection by isolating risks to individual assets, with income and expenses flowing through to your personal taxes on Schedule E.

This does not align with buying most buildings in cash.Once you progress in your investing efforts you may come across more UHNW individuals, family offices and institutions who would take the lower return for limiting risk (all cash deal).

The Homeowners Insurance will include Builder's Risk. 

Underpriced, underperforming, value add, 20 units, cash flow potential, low risk How did you find this deal and how did you negotiate it?

And therein lies the risk of high-leverage.  

Are there any potential risks or downsides I should keep in mind before proceeding?

There is more messiness and risk.

But let’s go a later deeper - my down payment would come out of a well performing stock portfolio.

That's one of our biggest risks it seems, however, ND is more friendly than the MN side.