I am glad you like NC so far.
Behaviour Trees are indeed mostly great for AI behaviours rather than general game logic. Certainly doable, but not what they are ment for. Dynamic AI is where they shine 🙂
The Dialogue Tree is motly like Decision Tree, but I specialized it into a dialogue tree since I wanted for it to handle actors more intuitively and have more specialized nodes, but at its core its kind of a Decision Tree. I will provide an extra generalized Decision Tree System in the very near future though.
As a side not, I am working on an NC based system (XpressionCanvas) which will work similar to XPresso (Cinema4D) and ICE (Softimage) with per-port handling (image attached). Still, that is quite different from UScript for example, mostly in the way/flow that the nodes are evaluated.
I will provide a BETA when its beta ready, to all NC users that want to test it.