You're the same guy who would (admittedly) steal a deal from someone else, so please spare me the superior ethics routine.

- a nice round figure that seemingly would cover routine damage (e.g. $500)?

Claim the routine cleaning was not done according to the warranty instructions.Most companies have a foot note that says “lifetime” = 50 years.

@Mel Griffin  the Old Joe Kaiser hooked on Overages  routine... counties are really cracking down on that activity.

Try living in upstate NY where property taxes on a $100,000 house are routinely $3,000 (town, county & school).I'm headed to the assessor's office next week to try to work out an agreement for a drastically lower assessment on my primary residence that I bought in July.

Over the life time of ownership, between interest, taxes, insurance, maintenance, routine upkeep etc, the home will cost more than it will ever be worth during a individual life time. 

Either they leave because they want no increase and they can find a cheaper place or they stay knowing you are going to routinely increase the rent as your costs go up. 

where i invested they routinely walked up resale values on property 5-10% a month for several years like clockwork.

I do not like electric stoves they routinely burn out elements, folks get burned because they cannot see they are hot, they cost more to run, they leave tupperware on the burner when they turn it on, they keep a more even heat, etc.

-Routine inspections.