The scene transitioning is a bit weird. The behaviour you created cannot work properly because during transitioning, your actor would still be inside the region until the next scene really replaces the current one.
I'm far from being an expert yet, I've just started to learn how to use Stencyl but I'm training by doing a little "2D Zelda" work to experiment. In the same way you did, I created a behaviour associated to each of my scene thant handles the detection and the transitioning of the hero. But I went in a different direction. I'm not using regions (I prefer to keep them for doors for example) I'm using screen or scene boundaries instead.
You must pay attention because - in the same way I must have faced it - it is possible that your logic still runs before and during the transitioning. As far as I'm concerned, if I were to get to the screen on the right for example, my hero would go by two screens instead of one. And in an earlier version, I also had my character transitioning back and forth between two screens haha ^^
Try to define a proper way of transitioning, you never know, it could solve your second problem.
