This stuff will hit you if the things were done without permits..

From simple rules like permits to outright bans so that is a huge risk IMHO.

Our local towns and rental assistance programs really appreciate those that try to work with their tenants which has helped me several times through easier permitting processes.

If your leasing application process is thorough and well thought out, and if your lease agreement has been well drafted by your local attorney and if it includes clauses that permit you/your property manager enough latitude to maneuver and anticipate undesirable tenant behaviors, both actions and inactions, and you have operational processes which align with enforcement of your lease, then you've done all you can do to reduce this inherent risk of an undesirable tenant.  

GC never pulled any city permits yet charged me (didn't find this out until the job was finished). 

I have 10 water front lots on a trout river in WNC with mountain views, they are cleared. i have the site permit, i have the well and septic permits.

Illinois just legalized recreational weed, however some of my tenants have been smoking it in their apartments long before legalization was even a consideration. 

If they are separate, permits would have been pulled and the city will have records of those permits.  

The last you want to do is make an enemy of the firemarshall as they could permanently pull your permit to be able to rent at all.

Duplex Development Made Easy - SB 9 permits property owners to convert single-family lots into duplexes.