Switzerland is not a part of the EU.
[1] http://www.schengenvisainfo.com/schengen-visa-types/ [2] http://www.schengenvisainfo.com/frequently-asked-questions-s...
No, they generally don't.
I named their permit incorrectly: should be "residence permit" instead of "residency and work permit". The point remains that EU citizens generally need an official permit to work in Switzerland.