There is certainly a stain in that picture, but the photo itself does not appear to reflect mold. 

The tenant attempted to clean the oil stain using a commercial cleaner, but was not successful.

Every wall had to be repainted (not sure how they got so dirty, stained and scratched).

I hoped all the stains would com out but wasn't holding my breath.

By doing so, you attract 4 year juniors, 5th year seniors and graduate students, kids who are typically more responsible and not only want a nicer place to live, but also will take more interest in maintaining the quality of home.I say no carpet because even the best students will spill and stain carpets and it lowers the quality of the home when showing new potential residents stained carpet.

We can easily show the stained carpet.

I have stained/sealed concrete in my newest rental and it's held up pretty well so far.  

Stained or just poly-ed cabinets hide imperfections much longer.Painting cabinets is not expensive but it adds up and adds time to turns if you scale to more properties.

My lease states (removed the parts not at all applicable):Deductions:(a) damages to the Property, excluding normal wear and tear, and all reasonable costs associated to repair the Property;(b) costs for which Tenant is responsible to clean, deodorize, exterminate, and maintain the Property;(f) unpaid pet charges;(q) cost to restore walls, flooring, landscaping or any alteration to the Property not approved in writing by Landlord; and(r) damages to the Property caused by smoking, including but not limited to stains, burns, odors, and removal of debris.Here's a photo of one of the door frames, for example.

I bet they like cash :-)They could be stupid and get greedy and stubborn.