You'll need to have a legal agreement between your two LLC's to make this happen and prevent piercing your corporate veil. 

Is it a sign to have outstanding issues prevent the completion of the inspection til just before the DD deadline?

See if Google can find you a template to get you started.I'm sure there is something out there to prevent starting from scratch.

As mentioned above, you have let this get out of control in so many preventable ways. 

To many precautions are built in to prevent it.  

I grabbed an ical to prevent double bookings and handled all support of guests I booked, so there was no overlap or confusion.  

Some cottage areas or municipalities have by laws or restrictive covenants in place that will prevent you from operating the unit as a STR.  

Here is a brief description of it:https://malegislature.gov/Bills/191/HD5166Protecting Renters and Preventing Evictions-Cancel/ban evictions for rent due from the start of the COVID-19 State of Emergency through 12 months following the end of the State of Emergency, if tenant was unable to pay because of a direct or indirect impact of COVID-19.

Is there a fair housing law that prevents me from stating that I would not rent to tenants from section 8?

There might be some language that prevents you from doing what you propose.This is a good idea to add value to your company.In any case, please post when you have an update.