Yes you would.
Yes you do.
passport
Depends. If you are flying from Honolulu, you do not need a passport. However, Since Guam is technically part of the United States, you do need to show proof that you are from the US. (Photo ID, Drivers License, etc.) If you are flying from a foreign country, you will need to go through Customs.
Guam is a protectorate of the USA, but is out of the country. I think you will need one. You can check at the post office.
If you are a permanent US resident, then you can enter Guam no problem. It is a part of the US and you do not need a passport or visa to enter.
I don't believe so since Guam is a US Territory. However, you should probably have one to be on the safe side. If your flight gets diverted by chance, you won't be able to leave the airport to go to a hotel.
This depends entirely upon where you are coming from. If you are flying within the US then no. If you are flying in from another country then yes.
Entry requirements for Guam are the same as for any U.S. destination. Although U.S. citizens are required to possess a U.S. passport, on a case-by-case basis, photo I.D. and proof of citizenship may be accepted.
The law changed a bit a minor can have there birth certificate and other documents. If you are traveling by air you do need a passport also by land it is recommended.
Provided that travel is direct and does not include going anywhere outside of the United States and its territories, a US citizen or permanent resident does not need a passport to enter Puerto Rico. The same applies when visiting Guam, the Virgin Islands, American Samoa, Swains Island and the Northern Mariana Islands.
You need a passport to get a visa
You need a passport