By reading this I can see that you don't understand how LS settings are used. They are read in during LS startup and stored in memory locations. For exmaple, you have an array for PopupTitleText with the value of Title. So reading branches of a XML document will just slow you down. Since settings will be stored in memory this way no matter how the config is done, having something structured for the machine doesn't help anywhere.

I still don't understand how user config apps will benefit by writing XML vs. Flat text. I have done a lot of programming with Flat Text files and it is really easy to write "$VariableName$ $VariableValue$".