As far as safety goes I can't really speak to that, but to my knowledge it wasn't an issue.  

It also allowed me to add more money to my 401K and IRA accounts to increase my margin of safety in case we ever have another financial crisis.My path to financial freedom followed the one described in the book "The Automatic Millionaire" by David Bach: get a good education, get a good job, live below your means, and save and invest the rest.

The other tenants I explained as empathetically as I could the units were in very bad shape and presented health/safety issues.

Safety Measures: What are some essential safety measures I should consider implementing, such as pool alarms or fencing?

While we prefer not to evict, we've never had a problem evicting for either non-payment or health & safety.

And, since these will all be employees, you need to designate a Responsible Safety Officer that would develop and implement your Safety and Wellness Program.

Some say they stay clear of D neighborhoods often referencing safety and comfort as a concern.

Be happy to break even years one and two, then you have some safety to make more adventurous moves. 

Their concern is going to be the safety of the kids. 

You're offered certain degree of safety, but it is not free to you!