Is it possible to do it.
If yes need a small guide. :)
I don't think there is any support for reading compiled xml files in vcmp.
But yes you can properly compile xml files
https://msdn.microsoft.com/en-us/library/bb986817.aspx
What's the point though? XML doesn't have any logic. You'd just save it in binary form. Which can be loaded back and saved as text at any time. It's not as if it would that hard to decompile. In fact, it'd be the easiest thing to decompile.
xml of maps?
sadly player's camera is not working correctly with streamed objects (camera works like objects has no collisions and camera not avoid the object)
it would be good way to save/ingame editing maps to use streamed objects instead static maps (but it will load server a bit with big maps)