"Well, I agree that everyone on the continent dying is bad, but commanding ridiculously powerful supernatural entities could also do really bad things and I don't know the scope of those things. Isn't there anyone besides Ulmo who'd know more?"
She couldn't do that with sorcery! She'd have to cheat with a bunch of fairylights. This is cool.
"...There's foods with medicinal properties? I'd get bored if I ate nothing but one thing, maybe unless it was haws from my tree? What's protein?"
"Not really? Just commonsense stuff I picked up from learning transmutation, and, like, 'if you drop things they fall'."
"Metals are more like each other than they are like other things, so it's easy to transmute a metal into another metal, that sort of thing. Mercury's harder because it's liquid."
Now, if you take all eighty things - some of them only exist in Valinor, so it'd be hard, but if you did - and you write up their properties, you get certain regularities. In particular you get regularities in how they link up with each other and with other things. Metals are kind of a category of regularity. So are gases. To make this simpler than it really is, the regularities come from how many other things they'll connect with - like, imagine everyone has arms and they use those arms to catch hold of other essences. Carbon has four arms. Helium doesn't have any.
Most of the world is made out of essences holding hands, or floating around freely if they're the kinds with no hands. They're only stable if everyone has all of their hands occupied. Does all that make sense?