Only if you're travelling by air.
yes you do in order to travel you must have a passport
No, both the UK and the Channel Islands are in the common travel area meaning that immigration control is not used.
well that depends. If a baby is under 18 months then it will not need a passport. I got my first passport when I was 5. Babies usually get discounts at the airport. Channel islands or Canada, a baby does not need a passport if it is under 18 months.
NO U DON'T.
There is no such thing as an English citizen. If you were born in England you are a British citizen (as described in your passport).
Yes if you are leaving England then you must have a passport.
If you are flying from the UK to the channel Islands it is ok.
Yes
That will depend on your nationality.
Yes.
Where you are travelling from or to is irrelevant, it all depends on your nationality.
Yes you do if your coming back to America