Just caught this post, and would like to actually congratulate mrsMxyzptlk on this catch. I *never* liked that they had Lois call him "Daddy" in the show, and even though I've never written a direct scene between the two of them in a story that I can recall, whenever I have her mention him (or think about him), I usually refer to Sam as "father" or occasionally "Dad". Coming out of a frighteningly similar situation, I personally will admit that I can't find myself ever in a situation where I would call my father "Daddy" and the only times I'd used it in the past was when I really wanted something (sweet talk him into an ice cream before dinner or something). But I was also younger then.
It's likely just an issue of the way the individual writer views the term. To some it may seem natural, or simply affectionate, or fake or what have you. And also it probably was used (originally/in the show) to demonstrate how Lois has a stunted relationship with him-- but again, I personally never felt that was an accurate representation of Lois.
That's just my two cents though.
