With less than 50% being owner occupied there is a very high probability that the building could deteriorate considerably.

Trim the branches and tell them it was causing deterioration to the roof if they say anything.  

Since the tax foreclosure process takes about a year+,  they sometimes deteriorate significantly since I last saw them.

What I failed to realize with my online analysis, is that this strip of houses was on a block that was filled with section 8 tenants in houses that were left to deteriorate over time.

Of course, I am just a newcomer, so this is largely speculation, but I am well aware that the money I reserve for REI will deteriorate quickly once I begin to invest.  

He may be a "slumlord" because he is tired of landlording and has let his properties deteriorate, along with the road.

IF I'm able to find that out, how to approach the institution and show them that the property that was in livable condition when they made the loan is now in a deteriorated and inhabitable state where the amount of work needed to get it back to livable standards is significant, hence I'll take the property off your hands but it's going to be well below market value and you are going to be losing a lot of money.

They are disbursing those funds as a means to stay rapid property value deterioration in certain geographic areas.  

After you cut out the soft of deteriorated floor sheathing you will be able to see if the water damage has also deteriorated the structural floor joists. 

If the leak is coming from the toilet, there's a good chance that the toilet was not seated properly on a wax seal and water is escaping and deteriorating the floor.Putting legality aside, both you and the tenants are interested in fixing the problem. the tenant also wants a functioning bathroom, which isn't compatible with a drawn out repair.stopping the leak is your number one priority after closing, and it's causing the subfloor deterioration.