What if a couple of gangs decided that the boarded up houses two streets over look like great territory to setup a drug house inviting far more crime to your area?

There are suburbs with McMansions, rural farmland, world class universities, dangerous inner cities, gentrifying smaller cities and working class communities all smashed between New York City and Philadelphia. 

The dangerous item, is in how your respond.

With cash-flowing properties, you have to pick properties that are solidly middle of the road: they won't have the absolute best of everything (or they wouldn't cash flow), but you don't want dangerous properties either or you'll never see that cash flow. 

It's especially dangerous when using a percentage of a low rent amount. 

1st question is if you are in a dangerous Radon Testing Area:http://images.nationalradondefense.com/509/radon-zones-epa-map.jpgIf you are in a dangerous area, sometimes the mortgage company will make it part of the "due diligence".  2nd question is, is $150 worth knowing that you are safe? 

Real Estate brokers license. and the investor is domiciled in CASadly, I am assuming this is real estate attorney territory???

That is legally very dangerous.

Another danger sign.I do know how much I know about residential construction, and it took me quite some time to get to where I needed to be.

Single member LLCs are dangerous from an asset protection perspective.