Hello. As it has now become my itch, I've started working on separating out installation of the OpenGuides modules from setup of an Open Guide. I'm basing it on the way that CGI::Wiki::Kwiki works[0].
If you have a better way to do it, and either:
a) your way is less hassle (for me) than my way, or b) you are willing to do the work your way, and plan to do so within the next few months,
then please let me know. Otherwise I'll carry on with this. For the time being, I won't be committing this to OpenGuides svn trunk. I can commit it in a branch if someone would like to send me absolutely idiot-proof instructions for doing so.
Kake [0] CGI::Wiki::Kwiki can be found on search.cpan.org - it's almost certainly quicker for you to go and have a look at it yourself than for me to try to summarise how it works.