All of strawhats dream interesting with after final war.
To become pirate king , Luffy have to see after war.
To see All blue , Sanji have to see after war.
To become WSS , Zoro have to see after war and will fight Mihawk. (İf it happen before , ı dont know.)
To draw world map , Nami have to see after war.
To read all of ancient things , Robin have to see after war.
To see Sunnys world tour , Franky have to see after war.
Brook - Laboon.
Chopper - medicine that cure everything.
But , as a story , If Usopp will play significant role in the final arc and he dies , he can yell I become warrior of the sea . Thus , his dream will come true . and his story can be told generation by generation as a legandary. And that would be very impreessive and stunning.
I am not sure Lufft want immortality. Law will offer but luffy refuse him. And I don't get it what is immortality thing . Whatever happened luffy , he will become immortal , or he can be killed but in terms of age or illness, always he will be young and healthy.