The easiest solution is to run these two commands after installing Lightroom 5:
defaults write /System/Library/User\ Template/English.lproj/Library/Preferences/com.adobe.Lightroom5 firstLaunchHasRun30 -bool true
defaults write /System/Library/User\ Template/English.lproj/Library/Preferences/com.adobe.Lightroom5 RegistrationField_CountryRegion -string 1
We deploy with munki so I have it set as a post install script.
This sets the two needed default prefs that will get copied to each new user that logs in.
This assums you are installing via the pkg created with CCP.