Somehow i have a feeling one SH will die, probly Robin
Robin won't die.
She is the only one in the entire Op verse that can read the poneglyphs, not only do the SHs protect her but so does the Revolutionary army. She will be the one to come to the right conclusion once she has all the info, it was foreshadowed by Rayleigh.
The chances of a SH dying is extremely minuscule. Luffy already experienced the loss of a loved one, and came to the realization that he was weak and had a big mouth. He has said repeatedly that his 2 years of training were so that he could protect everything, same goes for the rest of the crew.
There is also the theme of realizing one's dream and being there for one another. If someone was to die under Luffy's protection, it would be a repeat of what happened after the war x10, and we don't need that. The SHs have trained, they are ready and will most likely overcome all challenges until the rest of the series.
That doesn't mean that there won't be lessons still to learn. I personally think that FMI will be destroyed by Big Mam, due to Luffy pissing her off and challenging her. It will teach Luffy that putting an entire population under his protection is a massive responsibility. I wager it will be the biggest wake up call for him during their travels in the NW.
I also believe Luffy will come very close to dying ( more so than the other times he came close to dying )
due to some exotic disease ala Roger. That would allow Chopper to realize his dream of being able to cure anything, something Crokus could not do for Roger in his final voyage.