Nice tutorial, especially the environment part.
Everyone dealing with classes in their scripts should check that bit out.
I would also like to add that you can access everything in the root table if you prefix the slot name with ::
. This will work in every environment (=scope), allowing you to use 'global variables' safely. In fact, you'll have to prefix LU native functions with :: if you want to access them safely within a class. Forgetting :: from a native call is a common mistake.