Locked cockpit door...
How long would the pilot hold out while the hijacker(s) executed the passengers, one by one, starting with children...?
Burly bouncers ...
Same as above, plus would they be willing to serve passengers? Or are they just "overhead".
No luggage ...
Would work. NO "containers" should be allowed in the cabin. Check everything. What is NEEDED from the purse during flight? Stock femine articles in the restrooms to eliminate the need to bring their own. ID and money could be carried in a pocket.