Those listed package are just those that have configuration files that hasn't been removed. Unless you are planning to reinstall the packages again, and want to keep the configuration, yes, you can remove them safely. In synaptic, you can purge them by selecting them all, use the Package menu, then Purge. You can do this from the terminal too:

dpkg -l | grep '^rc' | awk '{print $2}' | xargs sudo apt-get purge