Lewdest idea: Tooltip which locker does what. yeah it's in How to play, but it would be easier with just a tooltip.
Another gameplay improvement: gain points when deleting (changing) a locker, speed up time (maybe both behind a special locker purchase).
To calm the security level, I play nursery with passive lockers since there is noone passing by anyway (lure locker maybe?). It's boring as heck, speed up time would be great.