I think "Alert All Events" flag should be off by default after initial installation and should be explicitly set by user only for devices that needs constant monitoring.
Otherwise, if you have many devices (who doesn't these days :) ) as soon as you enable REPORT_MAIL = True flag in pialert.conf you get email every 5 minutes. I had to go and uncheck this flag one by one for all, but couple of devices.

Also "Skip repeated notifications during" should default to "1 hour".

Thank you for your effort and great tool.