Subsequently their relationship fell apart and are changing careers.  

It's a lot easier to make a case for discrimination if you let one person slide for something but not someone else.

As they develop more and more of a solid track-record, you can let Rental payments that are 3-6 days late slide a bit more, and offer other benefits such as reduced increases when their Leases are up for renewal, fast service when the maintenance calls come in, keep the hallways & common areas really nice, new  & clean, etc...In any event, professionalism is the key no matter what, imho.

If you can solidfy a well-oil machine for getting units rented, and subsequently turned over in the summer time for next year, you can have a very profitable business.College housing usually starts marketing their rentals in first weeks of the spring semester, with leases starting in the summer/fall!

If you ever run into a Fair Housing Tester who qualified per the rental criteria and lost out to a subsequent applicant you are going to have to explain that in a lot more detail  than I would ever want to.Most of us are not attorney's and would prefer not to pay for them.

If the inspector knows you and trusts you they will often let things slide with a promise that you'll be right back with that battery or they'll offer to swing back by in an hour or two to check that you found a drain pan and pass you. 

I did miss the reference to the "guest" in the subsequent post, and that does seem a little sketchy now that you point it out. 

My lease says 35 per pet per month...but I'm a sucker for animals so if they have two pets I might let them slide with just the 35.

You're not doing anything new or clever, you're just making my life more difficult because when one of my tenants has a landlord before me that deals with them in this manner, it's hard to build a good relationship with them.To reiterate my previous point, if you lose a hearing where you cannot justify having kept some of the tenant's deposit, there will be some record of that even if they do owe you money for utilities and are subsequently forced to repay you.

The rents come to my personal residence either by mail or in person, they just slide it in my mailbox.