I've commented before about the benefits to a prepper of being (slightly) paranoid. This article address what I mean and may help you manage your own prepper frame-of-mind.
http://prepperswill.com/prepping-reality-paranoia/There are aspects of prepper (and the less respected "survivalist" ) viewpoints which ought to be discussed among your group. The author lists some of these and discusses how we might respond to each. By no means an exhaustive analysis, but I found it worth reading.
Food for thought?