The wood weakness made sense to me - or at least it made enough sense. The lantern’s light is green, “like the growing things”, and Chinese alchemy posits five elements ( fire, water, air, wood, and metal) rather than the Greek four. In the earliest stories, it only worked on metal - Alan could be knocked out by a glass bottle - so that idea hung together well enough for me. The yellow business always struck me as arbitrary and silly.
And the ring should have a weakness of some kind. When Rayner was given a ring with no weakness, and nothing bad happened , it became hard for me to care about Green Lantern.
