@mixedbag: Palatino & Baskerville should be safe, but you'll have to switch them manually, based on the fc-override.tpl template.
I'm fairly certain this has come up before in this very thread, if you want more pointers

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Basically: copy linkfonts/etc/fc-override.tpl to linkfonts/etc/conf.d/98-override-custom.conf
Edit linkfonts/etc/conf.d/98-override-custom.conf *with a *nix friendly editor*, replace %TO_OVERRIDE% by the family you want to override (i.e., Palatino), and replace %TO_USE% by the family you want to use. Everything has to match exactly, case-sensitive, spaces, everything.
You can see the exact name to use in the KUAL Font Override menu, since the family name might not always be consistent with what the font usually goes by.
Once that's done, refresh the cache and restart X via KUAL.