When taunting Elias (a devout Christian) over his love of the Transformers, Randal refers to The Devil as "The Fallen". In Transformers mythos, The Fallen is as close to a Judas analogue you can get (Unicron being The Devil). The Fallen is even perpetually on fire.
Randal might have left the coffee pot on in a subconscious desire to help Dante change his life around for the better.
The choice of "ABC" by The Jackson 5 is not arbitrary. For one, it's a song about teaching, and Becky is using it to teach Dante how to dance (she even tells him to sit down on the line "Sit yourself down, take a seat"). More than that, it's a song about teaching someone how simple love is and it's this scene where Dante learns that he's in love with Becky simply because she's his best female friend.
It sure does take the fire department a LONG time to respond to Dante's 911 call about the 'fire' at Mooby's. There's enough time for the entire donkey show, Becky's arrival and her and Dante getting together and Emma's arrival and the end of her engagement to Dante.
A similar (but maybe less glaring) incident happens during the 'porch monkey' scene - after Randal inadvertently causes the two black customers to storm out of the place, the two other customers in line wait quite patiently when Randal gets his ears boxed by both Becky and Dante - to the point where the clerks (and indeed, many viewers themselves) become completely oblivious to their existence. Finally, the camera shows the guys again, who simply decide to give it up and just walk away.