While Gnome and KDE are finding nice fonts for cy_GB (Welsh) the OpenOffice package is using something I don't recognize that is not very nice at all. This is a default desktop install. Welsh does need accented vowels outside ISO8859-1/15 code space (Ŵ, Ŷ) which means that it cannot use vera fonts (there is a patched vera to fix this 'Olwen'), however it then seems to pick different fonts to the desktop.
It should not be using the Vera fonts. It should be using Nimbus roman no 9L. So, some questions: 1) Are you talking about the UI font, or the default Writer font, or what? 2) What exact version of OOo (rpm version, I mean)
The UI font. LANG=en_GB.UTF-8 oowriter - nice fonts LANG=cy_GB.UTF-8 oowriter - looks like a monospace bitmap font Also both log an error "Use of uninitialized variable in string in /usr/bin/oowriter at line 335" if that is relevant This is straight off the CD for FC3t2. The box is chewing away at updating at the moment.
OOo does not use X11 bitmapped fonts. When it attempts to get the UI font to use, fontconfig tells OOo to use LucidaTypewriter, which is a bitmap font. OOo then substitutes another font, probably Courier, for LucidaTypewriter because OOo will not use bitmap fonts. I'm not going to fix that at this time, but if you feel that another font on the system that we ship _has_ all the require characters (for example, the Nimbus ones), please file a bug against Fontconfig for this.