two different issues here...the hood insert is actually fiberglass, or some other fiber reinforced plastic material. It is bolted to your hood from underneath, so you probably have a loose nut, or the stud has come unglued from the underside of the insert. Pull off the insulation material from the the inside of the hood and check for tightness of the nut. If that's not the culprit, you'll have to take the insert out to verify if the stud has come unglued. Two hints - 1) the windshield washer nozzles act as bolts holding the insert as well, so you'll have to take those off. 2) Do not overtighten the insert when you reinstall it, as you may cause it to crack and also block the drains at the front corners.
Don't know about your door cladding, other than glueing it if one of the rivets isn't missing.
"If you're not living on the edge --- you're taking up too much space!!"