These cannot possibly be the most realistic failure cases you can imagine, are they? Who cares if "kids" "make illegal drugs?" But yeah, if kids can make illegal drugs with this tech, then actual bad actors can make actual dangerous substances with this tech.
The real risk is manifold and totally unforeseeable the same way that a 400 Elo chess player has zero conception of "the risks" that a 2000 Elo player will exploit to beat them.