I just boot them out if they do things like this or aggressively raise rent on them to compensate for their behavior.

As long as your landlord tenant laws, don't have any certain exemptions, you can collect first come first serve, or collect them all and choose which one you want based on their income, Credit, rental history, eviction, criminal etc... 

In some cases with professional administration you also have access to much deeper vetting of the sponsor that will include personal background checks covering things like bankruptcy, judgements, litigation, criminal history, and other red flags related to a sponsor that you would want to avoid.If that is not available, another approach is to talk to investors who have had an experience with the sponsor already.

I Use Keycheck for criminal, eviction and credit score background check.

They are total white collar criminals, living on yachts, and sipping martinis on everyone else's dime. 

They read our posts and it does have an effect on their behaviors, even if only a little.There is nothing embarrassing about a newbie being fooled by a more experienced person.

Clean criminal history and no evictions. 3x the monthly rent in income.  

I think I saw a discussion that was saying that criminal record might become something that you can't deny an application based on.

My father-in-law has a criminal record that cannot be wiped, is physically disabled and has paranoid schizophrenia.

Many places bar or restrict landlords from renting to convicted criminals.