When you enter a country, you have to have a passport--even if you are a citizen of that country.
No, because Northern Ireland is part of the United Kingdom. However, though not officially required many airlines insist on some form of 'photo ID. A passport would be acceptable for this.
A photo identification is necessary to fly from England to Northern Ireland. The airlines prefer a driver's license or passport identification picture. The passport is not necessary if the person flying is a citizen of either country.
yes
No sorry
Yes you do. If you leave out of state you need a passport
No. There is a common travel agreement between Ireland and Britain.
In theory, no. However, due to increased security in recent years, airlines will not allow passengers to board an aircraft without acceptable photo ID. The most acceptable form of ID is a valid passport.
WestJet do.
United Airlines doesn't actually fly to Galway, Ireland. The closest two destinations that they have from Galway are Shannon, Ireland and Dublin, Ireland.
You don't need a passport to travel between England and Scotland. They are both part of the UK. However, most airlines now insist that you produce a valid photo ID before you board an aircraft - regardless of where that aircraft is flying to. A valid passport - from any country - is the easiest way of doing that.
Yes, your passport.
That will depend on your nationality and where you are coming from. Generally though, for any international travel you should have a passport.