The subprime crisis of 08 crashed the SFR market and the use of floating rate bridge debt has caused huge problems in the commerical real estate space. 

Also, title listed the property as a 4-unit with only 1 structure, but it's actually a 5 unit with 2 structures, which is another thing that has me concerned.

Quote from @Terrell Garren: This caused me concern in the HUD lease addendum. 5.d.

If they are offering a General Warranty Deed then that would be excellent, a Special Warranty Deed would be good but not perfect as it would basically state that they didn't do anything to encumber the property during their ownership.One concern to note is that if the property never went through Probate, then there is always the risk that the property can go through the probate process unless it has gone past the statue of limitations or been acquired by adverse possession.

There is probably no perfect solution to all the issues.   1) The due on sale clause   2) The desire to keep a great interest rate   3) Her name on the deed\   4) Her name on the insurance policy   5) Her name on the MortgageSolving one of these issue can cause a problem with one of the other issues.

At the end of the day it may still need a demo if there is an improper install causing the leak from above, but I'd absolutely check all those other items and see if I could correct the issue first.

So when we did not receive any response to our emails for several days, this naturally triggers concerns and emotions.

My concern is the the long construction time and rising interest rates.  

Example: if you let emotions get in the way when you underwrote the deal the first time, causing you to overestimate the ARV and underestimate the rehab, then it's very possible this happens again in analyzing what the property should rent for.

Someone wants to come in and take pics of their home while they're trying to pack, then wants to come in and start performing work, potentially getting paint, dust, caulk, etc. all over their stuff - or at least causing them a decent amount of inconvienence?