Of course, the trouble is that "absolutely necessary to the plot" is somewhat subjective -- an element you or I might consider essential might be seen as totally stupid by someone else, or vice versa. I'm with you on not caring much for "apart angst," as Kathy calls it -- but then, I think an argument could be made that the angst in TOGOM *was* essential in jolting Lois out of complacency and forcing her to face her feelings. That's what Mayson was all about, as well, and there were certainly maddening aspects to that sub-plot, too. Which doesn't mean that anyone *has* to enjoy anything in particular -- I must admit that I haven't read F&AE because I really did *not* care for the NK arc.
I think you've got an interesting point, though -- that people rewrite episodes because they see a potential there that the show didn't explore. Even good episodes might have alternate ways of playing out that would intrigue a writer (ASU) -- and some eps are so bad that they just don't have any potential (IoM). So maybe it's the mediocre ones that really cry out to be rewritten.
Actually, sometimes I think that the entire series was just an exercise in how much potential could be wasted
Some episodes did very well, many others leaked profusely
But the underlying potential/premise is still fabulous, and flexible enough that we can explore literally thousands of variations.
Another question: Are there any really good episodes that have *not* been rewritten? I think DTOSC was one of the show's best episodes, and I can't think of any rewrites of it -- there are a few short inbetweenies, but has anyone tried to improve on major plot elements? Are there episodes that we love *so* much that no one can think of any possible improvements?
PJ