Trust me, I've suffered both symptoms.

My "Why" just got reinforced today when my diabetic mom told me she fell on the floor getting out of bed this morning due to a diabetic-related issue.

NO NOT rehab a property you don't own.If one needs to borrow the 1-1.5% of the price in option consideration, that is a symptom of larger issues.  

Most of these customers let me know in advance the model and the symptom so I have a few days to get the parts and schedule the repair between my other jobs.When it's laundromats or senior housing places, where everything has to be fixed the day they call, I always charge a minimum no matter how long the repair takes because I have to make last minute changes to my schedule to accomodate their needs.

Sorry I can’t be more informative, however we’ve not been informed by either tenant that there is an issue (e.g. slow drainage from sinks/toilets, gurgling or other symptoms of a full septic tank).

Not having money is a symptom of underlying issues.  

But what you're describing is going everywhere and not really a symptom (totally) of a bad broker.

Instead of just addressing the symptom (hair in the drain), see if you can create the structure to drive your tenants towards the behavior you desire. 

There could also be an issue with the auto defrost system and the water dispenser may be the first symptom.

Having said that, your average buyer is terrified of cracked slabs and foundations....Home Inspectors highlight them as horrible, so you may have problems selling unless you completely fix the problem....not just patch the crack (symptom) but really fix the underlying problem.