Hi list,
After doing some studying on my own I can now better rephrase one of my key
questions about citing e-mail and news posts.
Briefly put:

How do I make emacs: a) infer the fil prefix from a line, b) make paragraphs
a set of contiguous lines with the same fill prefix repeat count, c) protect
the fill prefix from editing?

I really like refill mode legally blind, it let's me concentrate on the text
rather than caring about line breaks. Snipping quoted text then becomes a
matter of setting the appropriate fill prefix and editing the paragraph in
question. I can also just regexp search for the next level n quote (
^\(>\s-?\)\{n\} ) and kill from my search start position to the destination
quite easily. Pretty nice.

The only things Emacs does not do is infer the fill prefix directly from
line beginning, set paragraphs to be equal to a particular quoting level
(fill prefix n times), and make sure that I don't snip the fill prefix (>)
when killing sentences, for instance. So the question is, can it do these
three?

Hi,
Oops, I ment the underscore not the dash. Not that relevant about my
question, but the regexp I
ment for matching level n e-mail quotes was:

^\(>\s_?\)\{n\}

[my RE knowledge is very much PCRE-based]