(One retired and other burned down.)

Being my first deal and a marine biologist who doesn't make much in the day job, I know I'm just trying to look at all angles so I don't get burned.  

I got burned with that one, died again just after the warrantee expired.

If you are not enforcing your lease and maintaining strict standards to train tenants to your requirements your are an amateur that will eventually be reputedly burned. 

And it helps prevent those unwanted 2am lock out calls.

While I think it's wise to game this out, I would not make any plans based on permanently low interest rates and cap rates, since that's a sure fire way to get burned.  

To your point you can get burned very badly if you cannot afford to diversify, but that's what happens when you play with fire while chasing returns.

Also, not many designers over 40 years old, high burn out rate.

however the 5% allocation does easily cover the cost of rental income protection. 3. did you know that only 0.4% of all structures in the U.S. burn down - Yet EVERY ONE OF US has fire insurance.      

Obviously he has been burned.