With this info in hand you can determine if it makes sense to move forward or call it a day.  

Should we address the situation with the tenant possibly having other people living there?

Basically, they name everyone because they’re hoping and counting on the fact that people set up their own LLCs and didn’t adhere to basic entity maintenance (operating agreement) and kept things separate (like bookkeeping and separate bank accounts).

People date for years and then all hell breaks loose when they get married and move in together.

Just google skiptrace and plenty of sites out there to research public info on people.

Sometime these arrangements fall apart quickly, it's hard to live with people who live differently than you and you don't really know how someone lives until they are moved in.  

People offer to pay cash up front or rent for a longer term in hopes of avoiding any scrutiny.

Before you buy you 1st build you awareness of real estate investing, potential team members that you will need over the journey that will likely last the rest of your life and commence recruiting people and investing time seeking out knowledge and WISDOM.Wisdom would say buy in the down cycles of the market and refi cheap when rates are low but investors often have ants in their pants.  

But reality is that some investors are so busy, they use people like me who do this full time to buy the properties for them.

Since it sounds like just a handful of locations, I would experiment with some repair strategies.