Hey Jen jen, you named all the things I was going to! As far as I'm aware, onions are poisonous both cooked and raw, though I don't know if tests have ever been done using organic. In the past, I have fed Casper left-over cooked vegan food that included cooked onion - even though it was in really small pieces Casper carefully avoided it and left the bits on his bowl. So I think they know!
As for macadamias, given how expensive and yummy they are I wouldn't want to give them to my pooch anyway, lol

Once again, I'm referring to my own experience here - 1 macadamia won't cause problems. A while ago I was sitting on the floor smashing macs with a hammer and someone came to the door - I left one macadamia on the floor out of its shell and when I came back Casper had eaten it! He was fine.
As far as I know peanuts aren't a specific problem but obviously they are highly allergy-causing in people so I'd keep a close watch on Sophie. That sounds so cute, her throwing them around!!

Definitely better than commercial treats.