Heck, you probably will need to do the same for internet and trash as well.

With  long term tenant I don't have the extra costs of full furnish and I don't have to supply the utilities, cable and internet.

Regarding the neighborhood, you can learn A LOT about a neighborhood via the internet.

And much of the region has no cell signal or internet.

I'm trying to convert my portfolio to such properties but don't want to have a high concentration in one area.

He has a sign in front of the property with his phone number to attract renters, but he does not currently have the property listed anywhere on the internet (no yelp, google page, etc.). 

I have searched this question on the internet and I found that if there is a renovation or new construction going on in the neighborhood is a one of sign.

Don't take legal advice from a stranger who isn't a lawyer over the internet : ) That said, I know of no place that you are obligated to accept any Sec 8 tenant. 

Always work with licensed/insured contractors and search the internet for reviews on them. 

Stop asking strangers on the internet for legal advice, hire an attorney, and put an end to this immediately.This should have been resolved the moment you discovered the unauthorized occupant.