Even when I flipped, I didn't put in the garbage disposal for three reasons: 1) I'm cheap, 2) it's not a deal breaker item, and 3) most people like to customize certain things (ala Tim Taylor, "more power") to suit their personal tastes.Regarding a tenant, garbage disposals are really just an excuse/temptation to be lazy and not take care of the plumbing like one should. 

I charge 10% on the balance after the grace period and never waive it because then they think they can get away with making excuses.

His rent is way below market so I'm raising it closer to market (still below, but not as bad as before). and yet he's using this as an excuse to want me to pay for painting the interior. 

Excuse the language but I think this will hit home for you and give you a little inspiration (at least it did for me). https://www.facebook.com/gary/videos/10153988204943350/

No matter what their excuses are.

I also could just use this as an excuse and remove them altogether and not have laundry in the building. 

And if he starts making an unacceptable excuse..."

Sounds like something changed for her and she's looking for an excuse, maybe some buyers' remorse? 

@Jim Adrian Please excuse my ignorance.. what items fall into "normal wear and tear" exactly? 

And you don't process their application fees, until/if you actually deny the one before them, and start to process theirs.This is to avoid any possible fair housing issues.And I learned to make appointments and if they were more than 15 minutes late without calling me with an acceptable excuse - denied.