Yes, you are moving between EU countries and so you need to able to prove your an EU citizen. Some carriers do however allow photo-card driving licenses as proof of ID. I would make sure you have a passport however, you don't want to ruin your trip. If you need a passport quick the passport office will produce you one in a day, you need to book an appointment and this service is at a premium.
Yes you do, even the travel to Ireland from the UK has now been restricted to passport holders only.
Not officially, but you may be asked for ID by Irish immigration officials.
no - it's an internal UK ferry trip
No
No. You can use any passport that is legally yours.
No but you will need photographic identity. Check wit the ferry company.
Nope - the only way to get to Ireland from England - is by either plane or ferry.
You would have to travel to France, and either get a ferry to Ireland from France, which is about 24 hours, or get a ferry from France to England and then another from England or Wales to Ireland.
By road or rail to a ferry port in France and then by ferry to Ireland directly or to England and by road or rail to Wales and then by ferry to Ireland. There are various routes you could take for the whole journey.
Yes you do. Whether you are leaving the UK by air, ferry or Channel Tunnel you need a passport and you also need one to return.
no
That will depend on your nationality. You may live in England, but have a different nationality, so you would not have the same conditions of entry as someone who is has a British passport. See below for details on getting into Ireland.