Was parking at the hotel free for all guests, did hotel parking involve having to give car license plate info to the hotel, and was there any control gate for entering and exiting the hotel’s parking lot?

Hotel parking lots, hotel lobbies, and hotel corridors increasingly often do have easily reviewable security camera footage.

If there were to be cameras in the room and the hotel staff could check such cameras this “efficiently”, that would be rather scandalous. Fortunately, that Is unlikely to be the case.

Personally, I would sort of dislike being automatically checked out of a room pre-checkout time and too early just because I’ve left the hotel premises with (some, most or all) my belongings or because my booked hotel room appears empty of people and belongings (beyond garbage) well before check-out time. It’s not all that rare for me to go check-in luggage for my flights and carry all my personal belongings while doing so, head back to the hotel room, and use it for work, relaxing, or to freshen up before returning to the airport for flying out. Maybe I should more often consider giving hotels a heads-up in-person the next times I do this, but even that isn’t a reliable way to keep housekeeping from getting started and even finishing cleaning up the room in my absence. While a DND sign may work better, it’s got it’s own issues and is not all that reliable to prevent the hotel from wanting the room turned as fast as possible even at the risk of inconveniencing some guests.