A few questions about Troy

I did not like the ending of the movie because I felt that it left a lot of questions unanswered. I would have liked to know: did any of the people that escaped survive? Did the boy that Paris gave the sword of Troy to get away safely with the sword? Will the people of Troy be able to rebuild the city some day since (I'm assuming) they still have the sword of Troy?

I thought Briseis was a virgin Priestess, she was found in the temple praying to Apollo, so why did she sleep with Achilles?

And my last question from the movie, why didn't anyone ever look tired?