Rough as in: Stockton is usually voted in the top 20 most dangerous cities of theFigure 2: Stockton, cesspool?

It also has fuses instead of circuit breakers which is problematic, expensive, cumbersome and potentially dangerous since they do not have AFCI capability and only interrupt the flow of electricity by blowing instead of "breaking" the flow like a tripped circuit breaker. 

Families who like to keep an eye on their kids generally like back yards / non exposed corner lots for safety mainly and to keep them away from the road and any traffic dangers. 

I knew it wasn't going to be fun and it was dangerous but it paid well.

A majority of the listing agents were baffled I was buying without an agent, and started telling me all the horrors and how dangerous it was.

What are the biggest dangers I should be looking out for with this strategy?

I live eight blocks from the gas explosion in the west village of NYC that just took down three buildings.

@Rick Richards, My opinion, after 40 years of successful real estate investing, is that 50% of all real estate guru courses are worthless, 45% are dangerous, and the other 5% vary from being marginally productive to very productive. 

@Everett StonebrakerYou have a prime example of the dangers, and general inutility, of CAP rates.We are in the same frame-of-mind as @J Scott  on including improvements (at purchase, before being put into service) and closing as the true cost of acquisition.  

Obviously the closer the 2 numbers the more dangerous the switch.