Inheriting it is the best option tax wise- because it gives you a step up in basis to the property's value on that date. 

This is a question that has come up a million times and will continue coming up forever in Chicago unless eventually things change one way or another.

(Yes it still happens, but it is a lease violation, and we have a solid leg to stand on should we need to pursue eviction or collections later.)

Cashflow goes up in smoke All the time. 

---Are you talking about having a backup Guest as an alternative in case the first Guest doesn't show up?

We bought a single family up here last year and converted a garage to an ADU, which rented out really quickly to a great young couple.

It felt reasonably if not underpriced to begin with and felt like I would lose an opportunity if I didn’t put in an offer for full asking price, they ended up being multiple offers the 1st day on the MLS, so I felt good about that decision.

Or can you still run everything through your personal return (just want to make sure that I can deduct things such as HOA fees which I can do if it is a rental).2) If I do decide to run everything thru my personal tax return (save on LLC fees), should I at the least set up a separate bank account to track costs separately?

I don't know enough about the start up costs associated with the ATM units but I am generally against businesses that have a short shelf life and here we have one we are fairly confident will be deemed obsolete. 

Transparency, daily & weekly updates and follow-up with all concerned parties.