Just don't tell them that you disapprove of it ;-)
It shows you hold a low opinion of your self image.
I suspect you are referring to confirming the details ? Apologies, I do not know. Whilst an international airline I suspect American websites might be more knowledgeable since it is an American airline.
do you mean give advance passenger information to them? Almost certainly; you have to do it for everyone these days, and it's basically an American precaution. I don't know about internal flights (within the USA), though.
if you don't provide your API to the airline, and it doesn't agree with the passport you present at the airport, you will not be able to fly. You also need as esta as per other answers.