I did find the answer for this without disabling Adobe XI Protected Mode.
I turned on the "Create Protected Mode log file" in the Preferences->Ehanced Security dialog.
I then attempted printing using my shell operation with both Protected Mode - on, and Protected Mode - off.
I then compared the logfiles.
It seems most of the files it couldn't access were in the %UserProfile% directory. One of the notable ones was Desktop\desktop.ini. Not sure why Adobe XI needs access to this file to print from the shell, but who am I to argue with the Protected Mode log file.
With some more research, I found these three settings as the most useful for application printing.
%UserProfile%
%windir%\temp
%windir%\System32\Spool\Printers (this is the one I noted in my first post)
With Enhanced Security, and Protected Mode enabled - these Trust settings allowed me to print from my shell operation.
So I am assuming that these trust settings can be added as policy settings from the server using Adobe Pro XI - if someone can post a link on how that actually occurs - I would appreciate it.
But these settings will certainly allow a single user to print pdf's.