So I finally was successful in making this a secondary site. Below are the 'things' I did that eventually resolved my install issues. Can't tell you which one(s) finally did it but these actions eventually got me there.
Installed KB2552033 for push on 2008 R2
Installed SQL Express 2012 SP1 first
Noticed several WMI errors in event logs on 2ndary site server that occurred during secondary site pre-req check that runs when adding 2ndary site from primary. That sent me down the WMI rabbit hole and resulted in installing KB2465990 to address the WMI errors I was seeing. Downloaded WMIDiags and ran that utility that eventually showed the errors mentioned in the KB.
Uninstalled all Secondary site Windows server feature pre-reqs, BITS, .NET, IIS, RDC and attempted install from primary again. This gave me the expected errors, the features I removed were the only warnings and errors.
Reinstalled site pre-reqs, restarted and then took another run at installing and was successful. No errors or warnings, site downloaded setup and installed successfully.
Sorry for the abbreviated resolution path, if you want to call it that, but I was successful after chopping the whole thing up and reassembling.