Probate, delinquent taxes, inherited property, divorce, health issues, tired landlord, dilapidated structure, looming foreclosure, etc.  

If your that worried about a leak or a heater going out I would take the money you save by not buying the warranty and put it in a cookie jar in case something pops up , kinda like a health savings account

Most of these item I would think I can catch pretty quickly, but definitely will test for mold and ensure that state/local health departments (specifically environmental health) certify clean.

If I could do it over again I would have moved to nicer and nicer multi-family homes (North Buff, Elmwood).I would think twice about buying in the 45-50k price range.

I work as a home health physical therapist and I mostly see geriatrics patients.

How much should one expect to pay for health insurance if they are a full time self employed real estate investor?

If you want health professionals put the distance to hospitals on mass transit. 

It gives you a certain peace of mind, knowing that no matter what happens with the economy, your job, your health, etc. that no one can take your house from you and all you have to come up with is the taxes and insurance.  

There are plenty of people who are good people who lack the education, capacity, ect to earn enough income to move to nicer areas but that does not mean they are not decent human beings who will take care of the property to the best of their ability. 

Regardless of the health risks involved in untrained people trying to work with lead, asbestos, or mold there are laws in place that carry large fines for violating them.