It depends on whether or not you are here legally. You will not legally be a citizen until you have lived in the US for four years after you have bought a home in the US.
You must live in France for several year while applying to be a French citizen.
If you have a green card and have lived in the US for at least five years; then apply for American citizenship and become a dual citizen of France and the US. Why giving up your French passport!?* If you are just a French citizen and do not live in the US, thinking about just exchanging the two nationalities with eachother, the answers is no.
Yes they can live together
Passports are issued by the country where you LIVE, not where your dad was from. If you were born in, or live in France, you will get a French passport to travel internationally. If you are a US citizen, to travel abroad you will get a US passport, whether or not your father was born in the US, France, or Mars... If your father is a French citizen and you are under 18, you're entitled to a dual citizenship, and passports from both countries. Some countries ask you to choose one or the other at 18. I do not believe the US or France are among these. You might check with the French consulate in your area.
Australian female citizen marrying US male citizen - which would be easiest marrying in US and come back to Australia to live or marry in Australia to live?
Yes, but the US citizen should sponsor his/her spouse's immigration in order for him/her to get a green card.
Permanent resident can apply for US citizen after live in US for 5 years (continuously and not leave the US in the period of 5 years).
You can but be aware, that the UK citizen cannot legally change their status while in the US. It depends on where you both want to live. If the US citizen wants to come back to the UK, a marriage visa is needed from the British Embassy in the US. However if the UK citizen wants to live in the US, they will have to go back to the UK and the US citizen will then need to file the I-130. Until it comes through you cannot live in the US, but will have to wait in the UK.
BY GOLLY, no!
yes
NOPE
Edmund Charles Genet was the French citizen that hoped to gain American support for France. During the French Revolution he was the French Ambassador to the US.