"A cron job will invoke a URL at a given time of day. A URL invoked by cron is subject to the same limits and quotas as a normal HTTP request, including the request time limit."
So you can't do cron tasks which last more than 30 seconds. Too bad.
I guess it is here just to show the power behind the plugin. I agree with you, there is no reason to implement such a complicated way to toggle help. But enabling up/down/left/right to navigate through images is sufficient and intuitive (and awesome). And that's why this plugin is all about no ?
So I guess the risk is low.