How to list Network Interface UUIDS?
First of all, to get the UUIDs of your network sets, use PlistBuddy and perl:

 /usr/libexec/PlistBuddy -c "print :Sets" /Library/Preferences/SystemConfiguration/preferences.plist | perl -lne 'print $1 if /^    (\S*) =/'


this should return the IDs of the network sets. For each set you can then get the name with

/usr/libexec/PlistBuddy -c "print :Sets:698F419D-326E-45E3-8BE2-B0742334DD62:UserDefinedName" /Library/Preferences/SystemConfiguration/preferences.plist 


where, of course, you have to change the UUID accordingly.
Now, you can print the ServiceOrder with:

/usr/libexec/PlistBuddy -c "print :Sets:698F419D-326E-45E3-8BE2-B0742334DD62:Network:Global:IPv4:ServiceOrder" /Library/Preferences/SystemConfiguration/preferences.plist


If you want to read the value for "ExcludeSimpleHostnames", you should be able to use 

/usr/libexec/PlistBuddy -c "print :NetworkServices:69F7441B-BA1E-4DC3-B7DA-8D6302986F20:Proxies:ExcludeSimpleHostnames" /Library/Preferences/SystemConfiguration/preferences.plist 


while of course replacing this UUID with a valid one from the "ServiceOrder".

Update:

don't miss that you can set values with PlistBuddy, too:

/usr/libexec/PlistBuddy -c "Set :NetworkServices:$serviceid:Proxies:ExcludeSimpleHostnames 1" /Library/Preferences/SystemConfiguration/preferences.plist