Under the US Visa Waiver Program a British citizen is allowed 90 days in the US without any special visas.
about 24 months
yes
They do. They just allowed my grand children who are Irish Passport holders on one.
If you are going on a cruise from a US port and the child is a US citizen, you will only need a state-issued copy of the child's birth certificate. If you are flying, the child will need a passport.
Canada got it's independence from the British.
Is it allowed to travel around the world with the world passport?
Oregan
In a passport photo, items or accessories like hats, sunglasses, and headphones are not allowed.
No
Yes, you are allowed to keep your old passport when you receive a new one.
Yes it is
No. You still need a passport because your are travelling from one country to another, therfore you would pass over a border and go through passport control, regardless of your citizenship to any given country.