@TheCrystalShip:
While I think this entire conversation was sparked by a misinterpreted joke (Brook is already dead, YOHOHOHO!), I have to ask… Why does Sanji's dream make it more likely for him to die? He still needs to get there, it's not any less important to him...
Because it's the kind of thing where he can go "I have seen All blue and know it's real" and then make a sacrifice for the crew. Luffy also has the thing with his dream implying he can fulfill it and die, like Roger. However, other dreams interfere with death.
Chopper has to remain alive to be the best, cure-all doctor, and I assume his knowledge will keep Luffy from dying.
Nami has to remain alive in order to see the rest of the world and chart it.
Zoro I guess could die, but to be the best swordsman I feel he'd need to remain alive to hold his title.
Usopp is supposed to return to Kaya to tell her the stories of all his adventures.
Robin is the only Oharan who remains alive, and the only great archaeologist. Once the veil of truth is lifted, I can only imagine she'd lead a new generation of truth seekers, maybe even become a mother. Not to mention her declaration of wanting to live would make her death really really awful.
Franky's fate is linked to the ship, which has to survive for his dream to be fulfilled.
And, as mentioned, Brook should be able to return to Laboon and play that whale some songs.
Granted, this is all assuming that Raftel would be endgame and anything after that epilogue, since most dreams are linked to getting there. However, it's not unlikely there's more after that revolving on what was found at Raftel, so that maybe most of the dreams linked to Raftel, like Brook's and Franky's, would have technically been fulfilled before endgame fights and their deaths could happen. Of course, it's also assuming that someone in the crew will die, which may not be necessarily true. However, I'd be surprised if Ace was Luffy's only major loss, and even though I think Shanks will also die I feel nothing would hit Luffy as hard as losing a nakama.