Though they try not to play it for sentiment, it is heartwarming that Debra is the one who can calm Corey down after her freak-out, since she and Corey normally can't stand each other.
There is actually something heartwarming about the resolution of the "Warren the Shoplifter" story-arc. Especially at the end when Mitch the Asshole Owner is yelling for "someone who works here" to come help him, and who should appear but Warren the Former Shoplifter.
Mitch: Doesn't anybody work here?
Warren: (hold up his employee ID, which reads 'Hi, My Name is Warren!') "I do!"
When the cops are about to take Warren out of the store, Lucas tells him not to let the man get him down and Warren thanks him, then calls 'Bye, Gina!' He seems to have a crush on her.
How about Corey and AJ at the end of the film? She goes up to the roof, pushes him down, yells at him, then proceeds to confess her love.
Earlier in the film, arty AJ was drawing her. She wasn't in the room, but the rendition is recongisable.
Joe and Lucas talk at the end of the film. Lucas' unplanned actions at the start now seem to have been a conscious attempt to make Joe happier, and the snowball effect hit everyone in the store.