Great neighborhood and simple cosmetic flip.

I'm not sure I would be buying anything right now if I were a beginner, for the simple fact that there is no need to buy  right now when one could wait ~90 days before making any decisions, and 90 days in real estate is nothing. 

If this is common in your area, then there might be a very simple solution.

Sweet and simple.

That simple strategy saves the landlord time, money, and risk.So, if you see a duplex that has two electrical meters then each side can pay their own electrical quite simply. 

I’m not a lawyer just a simple property manager but one thing (I think) that you could’ve done is that you could’ve had them agree in writing that they were converting their deposit into an ‘early termination fee’ or a ‘lease buy out’ Then none of this would’ve applied.

For apartment, we have options of simple sheet metal or RC-1 channel between walls and floors.

Or do just use a simple excel spreadsheet?

Unless your property hasn’t been maintained and something is always breaking it’s fairly simple.  

But even with the severity of coronavirus deepening, please make sure you have adequate amounts of food, stationary items, simple medical supplies, and immune system boosters (the best way to protect yourself from the coronavirus is to protect your immune system [Vitamin C, Vitamin D, sleep & adequates amounts of vegetables].