According to them their pay date changed so they agreed to pay rent late (on the 15th instead of 1st) and also pay the late fee each month.

As mentioned above, there are certain elections that you want to discuss with your CPA (assuming you are syndicate sponsor) to maximize date of death step up in basis of the asset(s).

I would be straight forward with the tenant and let him know what is going to happen and at what date and time.

Turnover date is May 1st but we are working with them to leave early so place can be cleaned safely after half-life of corona over.

I'm sure this thing is tough on a lot of people who were not prepared for it financially, or supply wise (W2 and Owner Operators both).The mandatory stay at home orders, food shortages, TP shortages, job loses, the uncertainty of your financial situation, having no job, or having to let some of your people go, etc...But it will end, and it may make it more endurable to focus on a possible end date. 

Some maintenance can be deferred to a later date, but if a maintenance request is an emergency and it needs to be fulfilled, social distancing best practices should be communicated to both the vendor and the resident.

Realtors, ourselves included are doing Facetime/Facebook messenger group tours with buyers/sellers virtually walking through every half hour on the hour. 

Yes, plenty of buyers are continuing their search for multifamily house hacks, I've done a few video tours for clients this week.

Ironically, it covers us better than a traditional deposit.Use professional photos and video tours.

As an architect this is going to come up when a lot of contractors cant meet their contracted due dates.