this is what scanelf says: dev-libs/atk-1.32.0-r1 dev-libs/dbus-glib-0.98 dev-libs/glib-2.30.2 dev-libs/nspr-4.8.9 dev-libs/nss-3.13.1-r1 gnome-base/gconf-2.32.4 gnome-base/gnome-vfs-2.24.4-r1 gnome-base/orbit-2.14.19-r1 media-libs/alsa-lib-1.0.24.1 media-libs/fontconfig-2.8.0-r1 media-libs/freetype-2.4.8 sys-apps/dbus-1.4.16 x11-libs/cairo-1.10.2-r1 x11-libs/gdk-pixbuf-2.24.0-r1 x11-libs/gtk+-2.24.8-r1 x11-libs/libX11-1.4.4 x11-libs/libXext-1.3.0 x11-libs/libXrender-0.9.6 x11-libs/libXt-1.1.1 x11-libs/pango-1.28.4 please check and update your rdep.
Still true for 2.26.1.
nss and nspr are false-positives (you have to set LD_LIBRARY_PATH=/opt/seamonkey , same as the /usr/bin/seamonkey-bin wrappers do), but the rest do indeed seem to be required deps. Same goes for firefox-bin and thunderbird-bin, afaict. I'll adjust RDEPEND in short order.
Fixed in seamonkey-2.30-r1