The loan is with you, not with your tenant, so none of that means anything to them - in fact because you live in one unit and it's under 4, if you were self-managing you don't even have to abide by fair housing laws (at least on the federal level). 

I have my primary property which is a single-family house that I house hack.

Looking forward to reviewing these options.Here's the PA law: https://clsphila.org/housing/security-deposits-in-pa/Any bank account will work.

The Yale Law Journal article, "Zoned Out: How Zoning Law Undermines Family Law’s Functional Turn," highlights this issue, noting that while family law has evolved to recognize diverse family structures, zoning laws have lagged behind, potentially hindering innovative housing solutions like co-living.Challenges for Co-Living InvestorsFor real estate investors interested in co-living, these restrictive definitions can lead to:Legal Barriers: Difficulty obtaining permits or approvals for co-living spaces due to non-compliance with traditional family definitions in zoning codes.Operational Challenges: Potential fines or legal disputes arising from housing arrangements that don't conform to local zoning definitions of a household.Market Limitations: Reduced ability to meet the growing demand for affordable, shared housing solutions.Advocacy for ReformThe Bloomberg article, "Why Are Zoning Laws Defining What Constitutes a Family?"

Any one of us could give you our two cents on the math of it, but only you can decide if it makes sense based on what your specific goals are. personally, i paid points on my house because my goal was lowest possible monthly payment.

Why did the former owner not execute this strategy? 

Anyone in NWA looking to house hack a 4plex?

Same with houses and the MLS.

I've called the attorney general and the city housing authority.

It is entirely different than a residential house.