Depends where you are travelling to.
If it's within the country or the EU then no i dont think so.
You don't need a passport but you will need photographic identity.
Consult the airline or ferry company.
If by ferry no. They will need some sort of id on a place.
yes
roughly an hour
No
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 but you do need I.D.
No. Passports are not required for domestic travel within the UK.
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
No, but it is a good idea to bring along some form of identification to be on the safe side.
you require photogrpahic ID eg, passport or driving licence, your airline will be able to provide you with a full list of appropriate ID's
Yes
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.