As to when you do the updates, you should really use behaviours, since modifiing the scene graph anywhere else will cause it to redraw
What do you mean by this? Doesn't behaviours also couse a redraw too, or are you saying, that if I modify say 1 object's transform group in a scene, that this will cause the entire scene to redraw? But if I use a behaviour, it will only redraw the object? The latter doesn't really make sense to me because if the behaviour can only redraw the object, then there should be a way that a non-beaviour method can redraw just 1 object.
Could you explain this?