I haven't used Safety Monitor as yet - still working on getting the hardware installed and such, so take the suggestion for what it's worth....
But I'm concerned about false alarms. My conception is to use pretty much every device in the house - contact sensors, wall switches and remotes, motion sensors, vibration sensors, etc. With more devices tied in, the chances for false alarms increase. Yet the larger the security net, the less likely any intruder could possibly evade it.
My idea... Make the system Bayesian. With the option enabled, Safety Monitor could allow setting a threshold number of points, and each device be assigned a number of points. Example, with a threshold of 10 points:
Locks - 9
Door sensors - 7
Window contact sensor - 5
Switches/remotes - 4
Vibrations sensors - 2
Motion sensors - 1
With 5 or more points inside n minutes, it triggers an alert, and 10 or more triggers an alarm. Of course, the number of points required, and for each device, would need to be set by the user, but with no one device triggering an alarm, it should eliminate false alarms. I wouldn't want to be alerted if a bird flies into a window setting off a vibration sensor, but I'd at least want an alert if my door unlocks or opens.