A loud-mouthed pizza delivery driver is pursued by the Italian Mafia when he steals their cash to impress his arrogant friends. EDIT: A loud-mouthed pizza delivery driver is pursued by the Italian Mafia when he reveals that they run his pizzeria to impress his arrogant friends.
As Richiev said.
If he were stealing the money because his sainted mother needs it for an expensive, life saving operation which she can’t afford because she can’t afford health insurance, then the audience would sympathize with her plight as it’s one that millions of Americans are in. So they would have a good reason to root for him.
But his motivation is egocentric — it’s all about him.
On the point that you are setting up the scenario to play out the character realizing that things can spin out of control, that’s hardly a unique twist or story hook. The best functional definition of a plot I ever read is: “The plot is a conspiracy against the protagonist”. So, of course, things go awry, the fit hits the shan. That’s standard issue plotting.