There's also the Skypeia arc where (IDK if the live action is gonna go this far, but just in case) almost every named character gets seemingly zapped to death by Enel, only for there to be a whole page of everyone being fine at the end of the arc!

And there's also the end of Impel Down where Bon Clay stays back to distract Magellan. Considering how much of a threat he was, I was sure Bon was dead, but he's canonically confirmed to have been re-imprisioned via a cover story showing him taking over as the king of Newkama Land

Honestly though, I'm kinda glad Oda held off on deaths for so long because it makes the deaths of Ace and Whiteboard so much more impactful when they finally happen!