When asked:

"Have your bags been in your possession since you packed them?"

I sometimes truthfully answer "No, I left them with the hotel desk for several hours after I checked out." They never bat an eye and it doesnt result in any different treatment of me or my bags (as far as I can tell). So what is the purpose of this question, then?

You talking about the ICTS interview before check-in (or at the gate) at airports overseas when flying a US airline?

I presume they're looking to see how you answer (behaviour), but if you told them it was sitting in a youth hostel for several hours that would probably get you a search. I saw someone use that answer once at London-Gatwick and the ICTS folks went through all the luggage this guy had first.

When they ask where did you stay? I believe they're looking for an immediate answer with a tone of confidence ... not a "Um, I stayed ......um.... at the Airport Marriott" (then they'll ask you to produce the receipt if you don't seem so sure in you answer). Sometimes they'll want to see it anyhow.

I don't like the ICTS interviews, but I have to admit, I've seen them receive some dodgy answers from other pax nearby that led to a hand-search of everything before check-in. They managed to stop Richard Reid from boarding on his first attempt, but when he returned the next day they cleared him despite failing the security interview the day before. (??)