in reply to Changing Perl Config settings
I've meditated enough, I've figured out what to do next. It looks like I need to get PPM working in the interim, look at flattening my include libraries, and do some work with compiling with minGW outside the CPAN shell. So I've updated the original post to integrate the most excellent comments.
Gratias sodales ab camelus
Update: here's what I found on PPM.