I concur that the capability to randomize on/off events is critical to making a dwelling look occupied when absent for long periods of time.
For simplicity of the user-interface I would hope that Vera would implement a “random” check box everywhere a time trigger was specified. Clicking the box would expand to indicate the time interval for the random event.
That seems to me to provide a more readable interface on when events will happen - particularly when reviewing items that may have been set some time ago.
( to go a bit over the top as a math junky, it would be very cool to be also able to specify the random time distribution which is used - not just a uniform distribution. But I don’t see much demand for such a statistical finesse)