You are taking offense that someone has suggested you contact an attorney, but this is precisely what you need to do, and do it now.

The tenants knowledge of the existance of the location of the heater in relation to the placement of their couch then proves they acted in a reckless negligent manner and contributed to an unsafe condition that could have created a fire!

A tip of advice, work for a placement that best allows tapping into existing waste lines, water lines are no big matter to run distance but waste has strict plumbing code that is distance impacted, as in inches matter, seriously.

Also, placement of the door doesn't match. 

Followed by tenant screening, tenant placement, rent collections, evictions, maintenance, unit turnover, deposit refunds, and repeat again. 

A Biography of George HW Bush -The Perfectionists: How Precision Engineers Created the Modern World-Spark: How Old-Fashioned Values Drive a Twenty-First-Century Corporation: Lessons from Lincoln Electric's Unique Guaranteed Employment Program-Good Profit: How Creating Value for Others Built One of the World's Most Successful Companies-The Great Mental Models, Volume 2: Physics, Chemistry and Biology-The Outsiders: Eight Unconventional CEOs and Their Radically Rational Blueprint for Success-Conspiracy: Peter Thiel, Hulk Hogan, Gawker, and the Anatomy of IntrigueWhat books have you read so far?

Also a Realtor might list it for a flat, one time placement fee, no costs if they don't get the tenant.    

Yes that's precisely how that works.

I agree 100% in what you are saying and it can create a problem You need to work with their placement officer or the responsible person (family, etc) and get it resolved.

I wouldn't expect a PM to do this, but I would hope for a higher quality tenant placement in the future.