If you received lots of bitcoins, like 100, and you are not comfortable holding them in your personal blockchain wallet, is it preferable to move them and hold them in a paper wallet for safety reasons?
Generally, keeping a paper-wallet is safe as offline, it's unable to leak to the internet. Obviously, you need to keep it in a way that it won't be available to visitors as well.
There are options to add a password to paper-wallets, which might help to deter casual discoverers.
Previously unmentioned: You need to make sure that you create the paper wallet in a safe fashion! If your computer were already malware ridden when you create the paper-wallet obviously the paper-wallet wouldn't be a safe storage either.
Yes. A paper wallet is basically nothing more than your private key on a piece of paper.
For usability it is often represented as a QR code though. You can make copies of it, and store several of them in different places, or even store half of the key in one location and another half in another. Bitcoins are never in your wallet, paper or otherwise; they are just entries on the blockchain. Your wallet contains only the private key to allow you to spend your entry on the blockchain.
It's safe, but I would suggest not let anyone know it's a paper wallet. And don't hide it in safes and all, because people won't usually even know it's a wallet in your home.