A new print-css.rocks release is available with support for some new tools: Typeset.sh
The Plone 3.0 TTW customization story is obviously better than I thought. Tom Lazar explains in this blog how to customize template-based views (very similar to portal_skins) using the new portal_view_customization tool...pretty cool. This seems to be one of the best hidden secrets on Plone 3. So with this knowledge my former blog entry is just obsolete (but perhaps it was worth getting some clearification). Thanks Tom!