i'm not going to speak of the mod_perl install setup, but I will say
this:
it sounds like a lot of the speed issues have to do with compile
issues.
mod perl speeds up serving content by caching the perl modules.
most people use a startup.pl file that is included from httpd.con in
a PerlRequire option. The startup script will preload all of the
Perl modules into mod_perl (ie: Petal / MkDoc / etc ). On top of
that, people will also run a perl routine to compile the Petal
templates. That pushes the time required to compile the modules
from the first request into the startup phase of apache.