Yes, airlines typically weigh cabin luggage on international flights to ensure it meets their weight restrictions.
In the overhead locker.
yes
The luggage compartment on a plane is typically located underneath the passenger cabin, in the belly of the aircraft.
The person who carry huge luggage into the aircraft cabin.
Generally, Yes. If possible, carry your laptop onto the plane as hand luggage. It is not a good idea to check a laptop in as luggage for the hold as it may be stolen by baggage handling staff. They can tell there is a valuable laptop in there because all luggage is X-Ray scanned.
It is possible that your luggage left without you.
..............................................................probably not.
It is in the baggage car and his cabin. However, you will need the key.
Yes, it is possible to book a flight without luggage for your upcoming trip.
nope, the luggage compartment as well as the cabin are both pressurized.
In the hold, beneath the passenger cabin.