I have a business plan that will be put into motion soon.

After reading the bylaws, they do have a right to enter in an emergency, but this is not an emergency to visually inspect smoke detectors.  

He also looks for other issues real quick like the furnace filter to ensure it was changed, that smoke and CO2 detectors are not disabled, etc.  

Hi Theo,I use the Nest smoke / CO2 detectors.

To their credit, a I noticed a few improvements had made on their dime (new exterior lights were installed and  motion sensored).

@Chris Reed @Joe VilleneuveI second Joe's motion.

Are there any Chicago landlords out there familiar with smoke detector code in Illinois/Chicago? 

Our inspection uncovered that the smoke detectors were battery powered.

Do you set up a computer at the property and connect the cameras to it and record everything when motion is detected so that you can review things later? 

In addition to replacing all fabric items, replace plastic items too that have become discolored or have absorbed the cigarette odor, such as outlet/switch covers, smoke/CO detectors, etc.A key factor is how long the unit has been affected by the cigarette odor and to what extent.