One major question: why is it called "script
format" when it's more of a bastard format derived
from true script format and prose?

Because there's no other thing to call it.

I think the only *true* script format I've seen is Chris Davies'
Together Again series of stories.

The thing is, many early (and I mean *early* - circa 1993)
fanfics were written in this "dialogue mode with a bit so
explanatory text disguised as stage direction".  I really can't
explain why, except that maybe one person saw it written that way
and decided to do it themselves, and so on.

There was no other easy way to delineate this kind of writing
from prose writing except to call it "script format".

And I still maintain that there are very, very few fanfics
written in "script format" that can't be improved upon by
converting them to prose.  I used to say there were *no* fics
that couldn't be improved such until I saw a fanfic by Sebastian
Weinberg (A Sam&Max parody starring Ukyou and Kodachi) that I had
to admit would be worsened by converting it to prose.  It was
only that way because it was very heavy on dialogue, humor, and
light physical action.

I still maintain, however, that "script format" is inherently
inferior.  I'd urge all new fanfic writers to write in prose
format.  I'd also try to urge old fanfic writers except I'd know
such urgings would be in vain.  ^_^

--Ryo Hoshi

-Richard