The trouble I had while debugging this issue had to do with how I was attempting to install packages from aports. Thanks to Timo and Natanael for getting me back on the right track.
Once I was able to successfully install apache2 from aports, I got down to business. I have an updated APKBUILD that seems to fix the issue of having extra modules being compiled in with the alternative "itk" and "worker" MPMs; "{httpd,httpd.itk,httpd.worker} -l" output looks correct, and they all start without modifications to /etc/apache2/httpd.conf, so I believe this issue to be resolved.
I also added the itk configuration to httpd.conf.
fixes#473
