I improved the explanation in the original post and added a much better example script. I'm working on a prototype NPC to better show it's usage.
I am also planning a graphical editor for creating trees without making any actual code to further improve productivity for users. A lot of professional game developers use graphical designers for Behavior Trees so why not us?
I know it may be a difficult read, but I've done all I can to make it clear, especially with the additional links. But I believe learning to use this is well worth it. Think of it this way: you should be able to create more advanced baddies easier and more quickly, and custom tailor your baddies easily to whatever situation you need.