Would TWOV apply to YYZ-DTW-PVG-DTW-YYZ arriving in PVG 10/28 at 6:55 PM and leaving PVG 10/29 at 12:30PM? Some places I've looked say 24 hour TWOV does not require country C, but I can't tell for sure. If not, could I travel if I don't plan to leave PVG (ie just spend the night in the airport).

If TWOV would not apply to that could I just book a random (possibly refundable) ticket PVG-TYO or something for the morning of 10/29, and show DL that at check in even though DL knows I'm coming back with them on 10/29?