Not normal, dreadful behaviour. You need to charge for the extra guests if that is how you have set up your system. If it says ''extra guests no charge'' then you can't.
Sometimes guests book for 1 but really mean 2, as in one couple. Or one bed.
I often find the back door unlocked, reasonably normal. I find dirty dishes in the sink maybe one in 20 bookings. Oven on? Bad. Often heaters and lights are still on. All these things is why it is imperative to go and clean as soon as guests have checked out.
I allow smoking outside so I often find cigarette butts, but in the ashtray provided...
In your feedback I would definitely say something like ''The amount of guests stayed didn't match the number who booked.'' This is not nasty but matter of fact and future hosts will be alerted to you being less than happy with the guests, or that they had a party, or whatever. Just don't say ''Lovely guests'' or we will think all systems are go!
Better luck with the next guests.