Without a grill, they can still jump up to try to grab the hood, but can't hold onto it. I've seen my igs jump up and slide off those aluminum hoods.
The usual reason for them trying to get close to the light is that they are too cool, and their bodies are demanding a 95F to 100F basking cycle. Providing the basking region in heir habitat, in my case, stopped the light-jumping behavior. But they still need the cool zone, at about 80-85F.
He's not eating because of prolonged Relocation Stress. As long as he remains healthy despite his thinness, he will start eating once he gets a bit more used to the sights, sounds, and smells of his new residence. Iguanas hate change. Try to not walk around near him, and don't give him your full face, which they recognize as a predator's stare.
He should see a good vet in case he is dehydrated. Dehydration is caused by not eating, because their food is so high in water. They don't naturally drink from standing water to counter their 'thirst', if they actually do have that sensation. In the wild, when it rains, iguanas suck hard on the water that's running down the bark of trees. That's a hard thing to duplicate in captivity.