Locking overhead bins will result in passengers stuffing their bags under seats. That might even impede evacuation as people haul desperately at their kit and others trip over loose items.
Best solution IMHO is for airline staff to shove $5,000 into the hands of every passenger who disembarks in an emergency without their baggage. That should take care of concerns around food, accommodation and replacement of laptops etc.
Expensive? Yes. But cheap compared to compensation for loss of life, and nothing encourages compliance like crisp greenbacks.