To fix the gucharmap failure, try running this as root:
# glib-compile-schemas /usr/share/glib-2.0/schemas
While the above does get run as part of certain packages' install scripts, it doesn't get run for gucharmap, which does need it. So depending on the order of package installation, the output files might not include gucharmap's required file. And if it is missing, you get that error.
Note gucharmap is on the Xfce menu as Accessories > Character Map. If you try it and it does nothing, check ~/.xsession-errors for the error above, and try running this command.