Please see the picture for any ideal which would be great.

Alex i think you are missing part of the picture. 

Do you have any pictures you could post?

Luckily, I haven't been in the situation yet, hopefully never, but here are a few things I'd do to make sure you have backup:1) Written statements from all exterminator companies, along with the bill, and showing how long it took you to respond, and get them in there2)  Written statements and pictures, from all 4 other tenants, showing the quality of apartment3)  Print off all correspondence,  specifically noting when the tenant showed the issue was resolved4)  Proof of payments-- showing she continually paid rent5) If you haven't already, or if she hasn't move, I'd write her a letter,  stating if she doesn't like the place, since she hasn't signed a lease, it's M2M, that she is free to leave next month at no charge.    

If you would like to see pictures I can take some tonight and post later.

@Chris Nordellacan you load some pictures, both inside and outside?

I would probably report it and document everything while it is still fresh - take pictures of the real walkway & the shortcut, etc.

Give the assignment of deed of trust to the trustee (servicing is out of the picture at this point, other than providing a payoff demand), ask them to record the DOT if you haven't already done so ... you are now the foreclosing lender continuing the foreclosure at the same point as previous note holder. 

The one where you can put the size of the property and then sort through various pictures of similar size layouts?

Do you have a picture of the finished marble lip/tub kick area to show?