Well, I figured out the 3rd question.
That is, "Start by Root Object" of Event Interaction is enabled by default. But my root object doesn't have collider and rigidbody. The Interaction Controller is attached to the root object as a child. So if disable "Start by Root Object", everything works fine.
And for the map event question, I will make my own scripts for it. Actually I had an idea about that, but just ask to check if ork can do it easily.
Thanks for reply.