Furthermore they sent out a message to all residents stating that they would not enforce the mask or distance requirements.Isn't it negligence and possibly dereliction of their fiduciary duty to keep safe and civilized behavior in their building?

Dribbles of cash flow from a dozen or so rentals will have negligible impact on your income and lifestyle, while it will definitely suck up your valuable time in low value activities.

If you are self managing, they can claim management negligence.

If the health and safety of their children is at risk, aren't they being negligent by staying in the home?

This just seems like gross negligence.

You still probably want an umbrella policy, possibly, but the extra expense of the LLC is negligible.  

I did this last year and the cost to get the loan was negligible plus all the interest you pay back to the 401k, not a bank or other institution.

The only time this becomes an issue is if you ignore the complaint or were negligent in finding a solution. 

There are many points in the sale where the HOA should've been discovered - if you were not told, it was likely either deliberatly being hid form you, or the people that were supposed to be assisting you through this transaction are on the verge of culpable negligence.

They have been negligent in letting the tenant be very late with rent every month and slow to fix repairs.