Taking the item away from the child, note to the parents regarding the food policy. Having to live their life knowing they sent something that caused harm or death to another child

It can be that serious for another child. I have seen so many parents act like lunatics over their "right" to send peanut butter for their kid and I seriously can't understand it. If you know you are putting another child at risk and do it anyway you are just an idiot and a cruel selfish one at that.
I think you might be the exception rather than the rule regarding peanut/food allergies. My ODS is entering 3rd grade and there have been at least 1 or more kids in each of his grade levels with serious food allergies and I know at least one serious peanut allergy preceded him into Kinder as the teacher mentioned it and one room was deemed totally nut free. My DH teaches middle school and has for about 12 years and he knows he has had several food allergies/peanut allergies over the years. My Mom spent almost 30 years in education and had plenty of allergies..some of them life threatening/extremely sensitive to oils/residue as well.
My YDS tiny preschool (as in less than 50 kids in the school) had one child with a life threatening allergy..he would react from being in the room with it/oils on the hands/objects. As in call 911 and use the epi pen reaction. The school was 100% peanut/nut free.
Plenty of schools or individual classrooms have a peanut/nut free policy and enforce it. If something is questionable (and really..aside from peanut products or products known to contain peanuts what is questionable about it? Nobody is going to snatch their ham and cheese and think it might be peanut butter..) then they might offer an alternative item and toss the questionable item. Really not that hard and lots of schools have done it.