In the final analyses it all comes down to Management. Its normally the same few kids who are responsible for malicious alarms or setting off extinguishers and someone always knows who they are. Usually the staff have a good idea themselves who it is and sufficient effort by management would probably nail the culprits 99 times out of 100. Visibly penalising the perpetrators or seeing them reported to the police would a better deterrent than any length of time spent shivering in the rain. (A few strokes of the tawse would have sorted them out in my day but, kids nowadays, mutter, mutter, mu...)
As to delayed calls, I'm stopping the practice of janitors running around like nervous sheep trying to find the cause of the alarm. If you require them to investigate then you must recognise that they may potentially be entering an area affected by fire. Consequently, you must provide them with relevant training (and, arguably, suitable equipment) to keep them safe. That is fairly costly and time consuming to do it properly. It's probably more efficient to concentrate on getting everyone out as quickly and as safely as possible and leave the rest to the fire service who have the training and equipment for it.
I also doubt whether a brigade nowadays would be prepared to accept a delay without a VERY strong argument in its favour backed up by a thorough risk assessment. Even then, the arrangements are only as good as the current management.
If the brigades ever do start to charge for false calls it may encourage some managements to take fire safety more seriously, not a bad thing! :twisted: