He should have brought the crew and tried to stop BM, or ignored her completely. His in-between response made things worse while showing he didn't trust or understand Luffy. When you say "Sanji chose to sacrifice his life" you don't really mean it the way I do I think, because if he had sacrificed himself he'd be dead.
There was no in between. He went out there to tell Judge to pick someone else to marry pudding, then when that showed itd be pointless, he decided to Sacrifice himself in order to save those he loved.
You have a really bad way of looking at sacrificing oneself.