Hi @Julie6183
Locks
Since you don't know where the key is, this definitely is a safety concern for you and any future guests. Guests will lose keys and you can never be sure they haven't made a copy of them. Suggest you invest in smart locks as soon as possible. The Schlage Encode or the Yale Assure are the ones many Hosts use. You can monitor activity from your phone wherever you are (even on vacation), add and delete codes and even open the door remotely from your phone.
Smoking
I would add wording to your House Rules about a $150 addl cleaning fee if evidence of smoking inside the property (be sure to take photo evidence and keep receipts for any extra cleaning). Also add If the smoke alarm is tampered with or disconnected, there is a $150 fine and your reservation may be cancelled with no refund.
Do not let on to the guest if you are preparing to claim for extra cleaning, lost keys, or damages until either they write a review, or you write your honest review right before the 14 day cutoff. I would write your review.