If it is vacant, you have written notice they said they'd be gone, either let yourself in to double check they are gone (and if so change the locks) or post a notice saying you will be there tomorrow to enter the place.Nathan's message is perfect about telling them where to leave the keys and that you'll be by to do the move out inspecting in the morning....also about telling them what to do, not asking.When they are moving there is a lot to do and it is better they focus on moving than getting multiple messages and calls. 

I simply tell them that’s nice it’s not for sale have a nice day.  

@Errol Graham you're in a tough position - too small for better software systems, but getting too big for spreadsheets.Stessa may be a decent option, as you should be able to track your accounting so you don't miss something or double enter a bill.Depending on the cost of QuickBooks, you may want to look into Buildium.

You can file a Chapter 13 which will protect your home and its a clean way out.When you file a CH.13 BK its not the end of the world it simply protects your home since its your homestead from foreclosure.

139,416 - 75,000 = 64,416.     64,416 / 9.3 = 6,926         6,926/75,000 = 9.2% annual ROI. or is it simply gross annual collection / purchase price?

- Can their system adopt special instructions like, where techs can access a master key to enter an apartment?

If you simply ask the tenant to resign the lease and then there were issues I could see them claiming deception to coerce a lease signing, so at minimum I'd likely shar with them there was a recent court ruling and you need to revise to make your lease legal.That said even if your lease is void I believe the tenancy would be governed by State law.

I have bought multiple properties personally, where rents were very low to begin with, and were even locked in for over a year, but once that renewal came up, I was able to simply raise the rent and keep the current tenant.

Do I need to provide a notice to Tenants that I will be on the property doing maintenance if I do not need to enter any active tenants unit?

So, I would presume that if a tenant sent a partial electronic payment I could simply refund it even at the court hearing claiming that I am not accepting the payment.