New US citizen born in UK

Hi, my American wife and I just had a baby in London. He is a US citizen (his mother lived in the US well over 5 years after the age of 14). I would be grateful if someone could help with the following questions:

1. How many copies of our marriage certificate do we need in order to apply for US consular registration of our son's birth and get him a US passport? Can we re-use the same marriage certificate for both, if needed?
2. How long does each application normally take?
3. In order to prove that my wife satisfies the physical presence requirements for transmission of US citizenship, is it sufficient to include her university degree certificate and social security statement (the latter showing over 5 years of contributions)?

Thanks.