[According to wallet explorer[/url], all 14 inputs belong to the same wallet (I'm not sure how the site determines that though). Seeing the ammounts of satoshis in the tx, it doesn't really look like a hacker may have been bothered; some of the inputs are as small as 500 satoshis; and to me, this just looks like a transaction to consolidate all your small inputs.
They simply use the fact that all the inputs are spent in the same transaction. And although the transaction looks like a consolidation transaction, it could equally be a sweep transaction where an attacker just clears everything in the wallet to their own address in one transaction. I would think they would he moved by now.
Not necessarily. Often hacked funds sit dormant for some time until people forget about them and stop watching the address. As above, if the output address is not highlighted, then it is not part of your wallet, and the likelihood is that either your device has malware or your seed phrase was compromised. 
