nope.
No. You don't need a visa. Prague is in the Czech Republic, which is part of the European Union. Anyone with any EU passport can go there without a visa.
does my passport need to be in date to go to belfast
No
No, Belfast is in Northern Ireland which is part of the UK - you don't need a passport to travel from one part of the country to another.
No
No but you do need I.D.
Yes
No but you will need photographic identity. Check wit the ferry company.
Yes, you will need to show your passport.
Not unless you need a passport to visit Weymouth.
You need a passport to go anywhere.