In my opinion you should be cautious of small mom and pop operators who are agents working out of their car because they just don't have the scale and resources to bring to the table.

I currently have 2 properties that are being rented without loans and recently closed on a business LOC so I have a cash flow source for flips instead of the cash roller coaster I was operating on.If it gives you comfort in owning a property outright, go for it. 

Why am I spending thousands every month on marketing and other operating costs for my deals when I could just pay $890/month and have deals fed to me!

It is by far the most expensive city to operate in - tolls, highest tax rate, inspection fees,  required utility deposits regarless of credit, etc.  

Also, tighten up your rehab budget so you can use it to lower your offering price also.https://www.hudexchange.info/resource/729/sample-development-budget-and-operating-pro-forma-for-a-commercial-and/or-mixeduse-nsp-property/

Poor turnkey or BRRRR operators that over promise and under deliver, you experience less than promised returns.

I know my landlord policy does not cover any sort of business operations in my rentals.

They are now mostly running our business operations from acquisition to disposition.

If you're inviting external investors to consider your deal, I would make sure I could answer the question of "is it legal to operate in the model that I am pitching?"

I thought uncollateralized loan interest could be written off as an operating expense in the year taken.