when trying to run gthumb: gthumb: error while loading shared libraries: libesd.so.0: cannot open shared object file: No such file or directory after i do emerge esound it works. so, esound ought to be a dependency for gthumb...
No, this is probably because you merged libgnome with esd and then unmerged esound. Gthumb links to libgnome and doesn't itself require esound in any way.