I know their habits can present dangerous living conditions and if they do not clean up...then yes, they do need to find another place. 

Even if you were able to get them habitable, the rent cashflow makes little to no sense, mostly due to economic vacancy.

And they seems to have a habit of moving from state to sate to state on a fairly regular basis.  

I would have an empty unit, inspected and found to be vacated and habitable, as part of my closing stipulations.

Bad habits rarely go away.

You don't know if his new career choice in his first week is trafficking sex slaves through austin....Or if he has a nice habit of blasting music at midnight....You get the point.....Someone without a steady full time job/school has proven trouble to me in tenants with too much time on their hands....

Each relationship is extremely vital to your current and future success.Good luck moving forward.

My focus will be on committing the tried and true methods of deal analysis to habit, and then integrating my creativity.

I usually get rent on the 10th-15th of each month and want to reign that habit back in by going to a $75 initial fee with $10/day additional.

Education and knowledge is always a vital part of growth and expansion.