It's just a preset when you start up your wallet. If you unlock it and then close it...it is staking with your wallet off. Anytime there after, just make sure you unlock it first thing when you open it so you don't make a mistake and close the wallet with it locked. I personally think this should be removed, if you're unlocked you're unlocked until you command it otherwise. It's a tad annoying.
Not if someone else gets access to your wallet it's not. Either in person or, remotely, lots of ways to steal your funds.