I have yet to have a stripper apply that didn't have a lengthy arrest record (generally drugs and prostitution) that disqualified her long before her source of income was considered.  

If they are recent I would be worried they are drug users and would be likely to break into other tenants units or destroy the building.

The important thing to me is that this isn't from drug money or something like that.

mhmm i know i love my RED STATES lol i also remember taking a criminal justice course and spending half the semester on intent and long story short is if you have a book bag full of drugs and you can prove you did not know they were there you CAN BEAT THE CASE... never actually happened as far as i know but basically if you grabbed your roommates bag by accident and they came in took the charge and explained it but i don't know anyone who has a room mate that is that nice lol MY POINT IS WHO CARES... not legal advice but if you accepted 2 applications at an open house at the same time and they both say they think they want to move in but are not sure... than you get positive reports for both perspective tenants and they both email you at the same time saying yea they are 100% sure they want it and will have a deposit the next day....

If they are not legal in your jurisdiction they are already in violation (and obviously don't care), so another statement in your contract won't make much difference other than to perhaps give you some liability cover.However, we did have a unit years ago where a tenant moved in a 'friend', 'cousin', 'pick your relationship of the week' who had automatic weapons, drugs and hookers.  

Our PM mentioned that the guy has an drug offense from a few years back.

She's not a drug dealer, but she is receiving a very large divorce settlement, has no income, will be going to nursing school. 

The building is overrun with drug dealers, dope addicts and gang members.

Drug dealers move in-- doesn't matter, no one will want to rent your house, or you have to make it dirt cheap-- but you can't control stuff outside of your own house! 

Basically covers deductibles, most dental/vision care, and most of the time you'd need to see a doctor or fill a prescription.