No.
No. None of the cantons of Switzerland have ever been under direct Prussian control.
Yes, Switzerland was part of the Roman Empire. There are many Roman towns, and other Roman remains in Switzerland. The best preserved is the Roman town of Augusta Raurica.
Only the western part of Switzerland.
No. Switzerland is an independent country.
Yes. Switzerland is considered to be part of Western Europe. However, Switzerland is not part of the EU.
No.
Switzerland is a country. It is in the continent of Europe.
No, Switzerland has never had a king. It is, and always has been, a republic.
No....
Switzerland is not a city, it is a country. Many of the cities in Switzerland have hosted many international events.
Switzerland has never been in a world cup final.