Hello
I'm finished with the clean-up. Have a look at http://http://wiki.openstreetmap.org/wiki/User:Datendelphin/NetzwerkSchweize... Thanks to FischersFritz for helping.
There were a few instances of other old, outdated imports by individual mappers (please at least write a mail to talk-ch before doing such things, and make sure it gets maintained. None of them matched the current outline any more). I deleted those as well during the cleaning.
The "Parc Naziunal Svizzer" is now tagged as boundary=protected_area with protect_class=1a, which I believe is too recent a tagging scheme to be rendered by standard mapnik style. It's the only park which could be tagged as national_park, which would be rendered. All others are not really national I think.
Have a nice weekend Michael