Ultimately he is responsible for his own safety so long as you are providing a safe dwelling; however, if he is endangering others you have a couple remedies as I see it.

As a lender, what is a safe amount of money to have saved in market where the average home price is 185K?

Conduct regular inspections and communicate clearly about the rules and expectations.Handling this situation firmly but fairly can help maintain the integrity of your rental property and ensure a safe and healthy environment for all tenants.

We practice "safe real estate", so this is all possible but not necessarily what will occur.This is not exhaustive and does not constitute any fiduciary responsibility, it is merely one man's opinion on a public forum.

If they dont deliver there safe to say it's a bad area.

If they were one of "the good guys" they would not take money from investors when they know they have zero real estate experience, cannot evaluate the risks presented by the investment or flat out say they are looking for a SAFE income producing investment. 

Are there any B and C class safe neighborhoods to recommend? 

Have a great weekend and be safe.

And it's worked for generations and the wealthy for a very long time because mutual insurance companies understand the human lifecycle quite well (law of large numbers), they're well regulated, make safe and sound investments and in several cases have paid out dividends consecutively for over 150 years (Mass Mutual, Lafayette Life, etc).

My IRA is just a fail safe at this point and STRs are where wealth is built.