Using some tests would make sure that the basic features do not get broken that easily.
To always correctly handle impulses, a interface should be created like for the behaviour and referenced behaviour nodes.
A plugin should be able to define which type is used to create behaviour nodes and referenced behaviour nodes.
The window should be much bigger so you do not have to increase its size all the time.
It would be great if I could replace an existing node with another one simply by dropping the new one on the old one.
Sometimes the items below do not get updated correctly.
It would be great if I could run a basic simulation of the tree, step by step. Allowing me to mark nodes as failing, any other succeeds. You should also be able to trigger events.
It would be good if you could add a description to behaviours so people know more precisely what it does.