Being in Brooklyn and the expensive market here, I am looking in Union City/ West New York area.

It requires keeping up on the local area's news, attending council meetings, keeping up on what's happening in the city you want to invest in.  

Find out from them what areas of the city are more inclined to generate positive income.

Additionally, with the City adopting the IBC 2015 and inspectors becoming increasingly difficult to work with, we've labor costs go up and soft cost on the design & engineering side go up as well.   

I worry about city/government restrictions on short term rentals, but am not familiar with current laws in Chicago.

Use city-data to see where the low income and below poverty areas are.

Is this particular property within Seattle city limits?

I recently acquired a duplex in Sacramento, close to Sac City College.

Too far away from the local college for walking (approximately 3 miles) and the property is located in a different city as the college which has a poor reputation. 

Here need talk to building department for address change. depend on city, some are easy some are difficult.BTW, in some Asian culture, 666 is super good lucky number.