In the United States, you need a government issued photo ID, such as a drivers license or a passport. Student IDs, social security cards, birth certificates, credit cards, employee IDs, etc. are not acceptable forms of identification because they are either not government issued, or do not have a photo. Most people use their drivers license to prove their age for the purpose of purchasing alcohol.
yes
A "We card" or another valid ID showing that you are 21 years old or older. There's a store that only lets you buy alcohol if you look sober.
No, if what you are purchasing is alcohol free there is no law stopping you purchasing it.
military id, passport, state issued drivers license or id
credit card
It's not "needed", but you will be asked to produce valid, acceptable photographic ID. Check with the airports or airlines involved as to what constitutes "acceptable ID".
Yes
Military I.D
State id
No, ID is like a license, or student ID. even a picture. A paper route is just a job/hobby.
Yes.
Theoretically no as Northern Ireland is part of the United Kingdom. However, acceptable photo ID is required to board an aircraft so if your journey involves flying, you will need ID and a passport is the most acceptable form of ID.