Assuming by a "European passport" you mean a passport from a country which is a member of the EU; then the answer is none.
Switzerland is a member of the Schengen agreement. All EU citizens (plus those of other Schengen member countries) are free to travel to Switzerland with a valid passport or national identity card without restriction.
Yes. You need a passport and it must be valid for at least 6 months AFTER your travel dates.
What do you mean by "Europe" and where are you returning to?? European Union passport holders traveling between the UK and other parts of the European Union need a passport. At present the passport can be in date or expired.
No, you cannot travel to Italy if your passport expires in 3 months.
No, you cannot travel to Peru if your passport expires in 3 months.
yes you can travel to France with a valid travel document such as Geneva 1951
No, you cannot travel to Colombia if your passport expires within 3 months.
No, you cannot travel to Jamaica if your passport expires within 3 months.
You always need a passport to travel abroad.If you mean a visa, the answer is still no, unless you count Turkey as an European nation. You are allowed to visit Turkey for up to 3 months without a visa on your Iranian passport.
no
Yes, you can travel to Europe if your passport expires in 3 months, as long as it is valid for the duration of your stay.
No, you cannot travel to the USA with less than 6 months validity on your passport.
Yes, you need to have at least 6 months validity on your passport to travel to Italy.