yes it does, just like everywhere else
To clarify that: Not for the country itself as Belfast is in Ulster, part of the UK, and you are a citizen of GB or Eire, or indeed of any EU state. You do though need a passport orequally recognised ID for airport and ferry security. Ask when booking what will be acceptable.
No
No
No but you do need I.D.
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.
You will certainly need a passport - since Ireland is off the UK mainland.
does my passport need to be in date to go to belfast
Yes
No, but it is a good idea to bring along some form of identification to be on the safe side.
As Belfast is in the United Kingdom and Dublin is in the Republic of Ireland, technically you may need a visa or passport to go there, depending on your nationality or other factors. However, there are no passport checks done on the train. Usually if you have been allowed access to Northern Ireland, you will also be allowed to get into the Republic of Ireland, but you need to check. See the website at the link below.
Yes, you need a passport to travel to Europe.
Yes, you need a passport to travel to Paris.
Yes, every person needs a passport to fly somewhere. no, you don't always need a passport! It probably won't if you flying are to Belfast from another airport within the UK. Best to check with your airline before you travel but infants on domestic flights can often travel without ID. You might need to take their birth certificate instead.