1) Definitely check local codes first2) Steel is silly cheap right now, and resists "tenant and neighbor behavior" quite well3) Consider a more substantial fence on property perimeter, such as block, and then more inexpensive options for interior yards.4) I doubt you'll get more rent, but you will have more interest, especially if other options around you aren't fenced.  

If we did a thorough background check already and paid for a credit report and criminal history report with the application fee, we don't give it back.

In my mind this negligent behavior from standard business practices has negatively impacted the operations of the property. 

What you would be doing is a criminal act.

And until that is solved, I will be using my extremely limited powers to battle that human behavior.

However, the renter does have to follow basic rules regarding noise, cleaning up, no aggressive behavior, no property damage, etc.3.

For example- We can't do criminal background checks until a tenant is conditionally approved based on credit in Cook County. 

Ask them if they are working, if they have a criminal background, etc. 

As you said it correctly, the point is not about taking the guests money but that the guests' behavior is very different for the majority of them if they have some money hold on the side that the HOST CONTROLS ON HIS OWN DISCRETION.

No evictions or criminal reports.