All you have to do is edit
/usr/share/rtcom-messaging-ui/smilies/user/default.deffile and remove all lines under
[Smilies]section. Same might be applied to
/usr/share/rtcom-messaging-ui/smilies/service/skype.def(or basically any *.def file within those directories). The next step is reboot and you have graphical-simley-less device in your hand. Hell yeah!
On the other hand, for those who actually love these ugly icons, *.def files allow to create mappings for new smiley icons, so for example you could assign "sad" icon to ":)" smiley just for fun. I didn't try that, tough, for obvious reasons.
Thanks to Nokian Mikhail Zabaluev for providing that hack.