As for the problem with vrms, the FSF people don't like it because of their
perennial disagreements with Debian. It uses Debian's criteria for freeness
so it reports things that FSF would consider free, such as GNU documentation
(which is licensed under GFDL with invariant sections). The name itself
implies that it uses Stallman's own criteria, which it doesn't. My personal
opinion is that the Debian/FSF situation is a matter of
more-alike-than-different; most of the things vrms will report are non-free
by both definitions, with the main exception of GFDL material.
As for how it functions, it will do absolutely nothing on Trisquel if you ran
it. It determines freeness based on a package's classification in apt. vrms
reports packages in the following sections: contrib, non-free, restricted,
multiverse, partner, which are where Debian and Ubuntu put their non-free
packages. Its usefulness depends on the packagers' willingless to mark it as
non-free, which usually means you get it through Debian or Ubuntu. Not to
mention a great deal of GNU/Linux proprietary software isn't even distributed
as a deb package.
I don't see a need for anything like vrms in Trisquel. Presumably you're
aware of every package you install, so you should take it upon yourself to
make sure you only install free software if your aim is to keep a 100% free
system. It's relatively painless to check: any free software package will
have a known free software license, if you can only find an "End User License
Agreement" (EULA) or no license at all then it is non-free. Take it upon
yourself to verify the license. In particular, don't assume that everything
that comes from a Launchpad ppa is free (note vrms won't flag anything coming
from a ppa either).
