Yes
It depends on your nationality. Switzerland is part of the Schengen Area. If you have an EU or Schengen area passport, there is no minimum validity. You can even travel to Switzerland on your national identity card, if you are from a country that issues them. If you are from a non-Schengen/EU country you need a validity of at least 3 months on your passport, and if you need a visa then you also need 2 blank pages on your passport.
Not if you are a citizen of an EU or Schengen Area country which issues national identity cards, then you can enter Switzerland using that identity card. Otherwise you need a passport. If you are entering Switzerland via the land borders there are not normally any passport / ID card checks, as Switzerland and all countries bordering it are members of the Schengen Area. But you still need to carry your passport or ID card as this is a legal requirement in Switzerland, and you might be unlucky and get asked to show it at the border.
It depends on your nationality. If you are an EU or Schengen Area citizen you do not need any time on your passport. Otherwise you need 3 months after the date you intend to leave the Schengen Area.
If you are a British citizen and have a British passport you do not need a visa to visit Switzerland, just your passport. The same applies to all other EU citizens. If you are a citizen of some other country but are resident in the UK, check with your local Swiss embassy.
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 to travel from England to anywhere outside the EU. You may need a passport, or other acceptable ID for countries in the EU.
If you are not a citizen of the EU you need a passport to enter Spain.
No, Switzerland isn't in the EU.
No - particularly those born after the UK joined in 1973 need no passport.
To obtain an EU pet passport, you need to have your pet microchipped, vaccinated against rabies, and get a health certificate from a veterinarian. The passport will document these details and allow your pet to travel within the EU.
No
Yes, You always need a passport (or EU national identity card) to get in our out of the UK.