One thing I not sure of, in the Wallet: File - Sign message; what is that?
If for some reason you needed to prove you are the owner of an address, you can sign a message with your private key and send it to someone and they can verify that it is you. Non-repudiation
Oh and make sure you have a backup unencrypted somewhere offline or dump the private key and print it/store it somewhere safe. Should something occur, either have multiple backups of the encrypted or other methods to recover.
Encrypting prevents coins from being sent should the system the wallet is on be compromised. They need passphrase to unlock. This can be key logged, so we are discussing other security option to address this.
Encryption is also required for staking I believe. The wallet needs to be unlocked to start staking.
Unlock option only activate once the wallet is encrypted.
Anyone ever tried to stake with an unencrypted wallet ? Maybe it's consider unlocked by default and staking is possible without encryption / unlock.