Why is Soap so knowledgable about knives? Because he's a chef.
The four lads, Harry, Barry and Chris all get an introductory narration from Alan. Nobody else does, because he's never met them. The same narrative trick was subsequently used in Snatch.
Winston is the only one of the cannabis growers who's stressed out. This could be because the others are mellowed out as a result of sampling too much of the product, but another reason for Winston's anxiety is that he's the only one of them who has to deal directly with Rory Breaker, which would stress anyone out.
Nick the Greek tells Tom that Sawn Off Shotguns are out. Dog and his crew use them as their primary weapons. They're all dead by the end of the film.
