I ended up becoming a soft well mannered programmer. Fuck you Thomas!
I avoid showing Fireman Sam to my 4yo son because otherwise he channels Nicholas—the self-centered, boastful troublemaker—so much that he's not manageable.
Norman Price? He always gets his comeuppance + a fire safety tip. Maybe have a chat after an episode to talk about what happened to Norman & what about his behaviour got him in trouble.
I used to watch episodes with my son (and comment immediately when Norman behaves like an idiot), but I can't watch every episode with him, and the fact that Norman gets comeuppance doesn't prevent my son from adopting his worse traits.
Also, IIRC even if the situation doesn't turn right for him, the chraracter rarely regrets anything beside getting caught.