I'd really appreciate your inputs.Some relevant info that may help- I'm expecting a size able bonus next yr from my stock vests (~$500k)- the house needs flooring to be replace since the previous owners put cheap laminate stickers that are coming off and counter tops and cabinet repaints. - homes are not renting quickly in my areas and even if they rent its below $2k. - there is a airbnb in my street which seem to have good occupancy Thanks in advance for all your suggestions.

The building stock is like all the other Chicago urban core burbs, so expect lots of 1950's and 60's construction with galvanized pipes, flat roofs, boilers and outdated electrical.

A long-term rental gives you a steady, predictable income as you ease into being a landlord.

Inspectors always make things sound really bad, that's their stock in trade.

Alternatively, if you're wanting to do something more aggressive, you could consider a balanced fund, such as Vanguard's LifeStrategy Income Fund (VASIX), which is 20% Stocks / 80% Bonds.

It is one of the best examples of City Council and local registered community organizations huddling together to create restrictions intended to thwart development but here they are doing it in a manner which will leave new housing stock in the dust relative to other neighborhoods thanks to terrible design restrictions.

Should I save and pay it off quickly or would the money be better in my pocket or in stock market?

As others said use low money down loan to owner occupy another and reinvest the rest into a another property/stocks. 

You can't buy stocks for a discount just because you don't buy them at the NYSE.

For instance, if you want to do 2-4 units then West loop won't work, but Evergreen Park or similar areas might due to the housing stock.