WITH-INPUT-FROM-FILE, WITH-OUTPUT-TO-FILE: don't like. :DIRECTION :INPUT / :OUTPUT is just as good, saved keypresses not worth the opacity. (This is something a lot of people end up macroexpanding, I think, because it is not obvious that there isn't additional magic going on.)
fwiw, since then i've extended them a little to help portability by treating :exeternal-format nil as the default external format.
COPY-FILE, COPY-STREAM: ok. (Don't understand the FORCE-OUTPUT in COPY-STREAM though: FINISH-OUTPUT or nothing would make sense to me, but the weak guarantee of FORCE-OUTPUT doesn't.)
:force-output was a thinko... those two names always confuse me unless i reread the docs.
pushed some fixes, including the docstrings, but it does not change my position on the issue, so feel free to move things.