Very interesting Gary.

I think a lot of it's quite good, but I'd recommend you describe
'constructive criticism' slightly differently. I'd say that criticism is
constructive when it points out problems you genuinely feel the story
has, and is phrased sincerely and not in an inflammatory way. It often
is very specific and may have a pointed suggestion, but sometimes it 
points out what you feel is a problem without being able to offer a
specific repair suggestion, or even without being extremely specific
about the problem.

For instance, here are three different possible constructive comments
about the same passage of hypothetical dialog. All three are
contstructive--some are just more useful. 

      "There was something about the dialog between Nadoka Saotome
      and Nabiki Tendo that just didn't seem right; I can't put my
      finger on what though." 

      "I think Nabiki's characterization was a bit to blas� in 
      attitude in her talk with Nadoka." 

      "I think Nabiki's being a smartass when she talks to Ranma's 
      mom. Couldn't you have her be more light, maybe make her 
      comment about the usual wackiness around the dojo more wry 
      than scathing?" 

Another thing to watch for is assuming that some manga element you feel
is 'cannon' should apply--this issue really tends to make people open up
their mouths and say, "you got this WRONG!" The author may be writing in
an anime continuity only, or under some other constraint. (If the
continuity/setting in the series timeline is unclear, you can always
suggest to the author that a note clarifying that detail is needed.) So,
to keep the comments _constructive_, phrase the feedback like "In the
manga, XXX is the case. Is your story using any manga continuity? If not
you might want to still keep it in mind."

So, with my definition of constructive, I'd say it always can be
constructive. 

As to the MSTing issue, I wanna say again for the record I personally
don't like them, and think that, per the Mystery Usenet FAQ, MSTers
should always ask first. I notice a LOT of people ask for MSTs and
that's great, but when they don't ask up front, or say 'give me -any-
feedback or comments on this,' you should ask. It's just good manners.

I think you should also add in something about the author's asking for
certain kinds of comments. It just seems to me that some commentators
have had a problem with authors only being interested in certain kinds
of comments (especially when the author has expressed what commentary he
wanted as the fic was posted...). For instance, some authors may not
care about spelling errors being pointed out to them because when they
post to the FFML, they aren't at the 'final polish & spellcheck' stage. 

Other times an author may select a continuity or characterization that's
not the most popular view, or have an element that they're just not
interested in having discussed and they want the comments to focus on
other things. I know it may seem demanding, but I think it's not
unreasonable as long as the author doesn't have tons and tons of little
details they want excluded. For example, suppose someone writes a fic
where the premise is that Kasumi's vacuousness is all an act to cover
for [insert pithy/quirky plot element here]. I'm sure that author is NOT
going to want that fundamental plot element questioned every time it
comes up. On the other hand, you can tell the author the whole thing
doesn't work for you, but keep it constructive: 

     "I felt the idea that Kasumi was [insert plot element here] 
     just didn't get developed convincingly, and left the whole 
     fic not working for me as a result."

Harsh, yes, but if it's your honest opinion and you're sharing it with
genuine feeling ... it's good commentary for the author.

Anyway, sorry I couldn't get more concise with my suggestions and
examples; I hope you can glean something useful from them though. 

Nightman