Visible crew/equipment: When Chuck is crawling on the floor of the plane to reach the watch, the compartment behind him where the raft was stored, you can see the stairs leading down into the set. (00:23:40)
Visible crew/equipment: When he collects coconuts for the first time if you look in the lower right corner you can see some sort of light flashing, I'm guessing maybe a light meter or possibly a two-way radio that the crew was using.
Answer: No one knows what was in the package. I think Chuck doesn't open it in order to keep his sanity. The package is his only link to his life before being stranded, working for FedEx and making sure packages get delivered. He was determined to make sure it got delivered just as he was determined to survive and get back to civilization. Success in one meant success in the other. While Zemeckis has joked there was a waterproof satellite phone in it, the real answer from the script is, no joke, salsa verde. Its a care package with a note imploring Bettina's (the artist) husband (naked cowboy) to come back and spice up their life like the salsa.