Honestly this feels more like a deconstruction of the tsundere trope and should be taken as a chance for the MC to point out to the sister how her constantly demeaning him to others had nearly fatal consequences for him. In a world like this where she's a famous adventurer, she supposedly was...
You'd think by that logic they should be able to just put the non-censored version when they upload to MangaDex. If their host/ad server doesn't want that, understandable, but that shouldn't be a concern on here at least.
I mean, rather than answer his question, they took a fighting stance. He wasn't going to take any risks if he could help it, so off to the afterlife they go.
I believe it's been shown there are some nuts that have negative effects, such as causing your body to constantly emit a foul odor or things like that. So just gobbling nuts left and right is not a good idea most likely.