Hmm, yeah, I should probably admit that I personally have a distaste for zombies (sort of like my strange and inexplicable distaste for coffee) which makes it sorta hard for me to see my characters' opinions clearly. I doubt it's a power Pietro especially wants to pick up, though, so he probably leaves Bobby and Wanda alone to do as they will.
True. I sort of feel like Pietro might have bits of any power after living at the school so long. I hesitate to make him too invulnerable, but that probably is the sort of thing he'd cultivate to the extent that he could. Just too useful for the kinds of things he likes doing :)
I think that's going to be a theme with Pietro. Sadly, or maybe luckily for him, considering, he doesn't listen.