I've heard some real horror stories about people trying to collect insurance claims on damaged items, particularly if the damaged item was a used bow. It's hard to prove whether the seller, the buyer, or the shipper damaged a used bow. Let's say you sell a used bow to someone for $500 and it disappears in shipping. Even though someone just paid you $500 for it, the shipper's insurance company will claim it wasn't worth $500! Imagine having to send back $500 to someone and only getting back $400 from the insurance company! The problem is, the insurance companies have figured out that it pays to hang tough; that the average person will eventually accept whatever they are offering rather than keep fighting it.
I think the only thing you can do is to overpack it so it wouldn't be damaged even if it fell out of an airplane. As far as getting lost, put more than one label on and even put a label on the inside. And then insure it anyway, since I think it has a better chance of being delivered if it is insured.