Hi sis fgnuva, about PSH's rings, I read somewhere that those are rings from Agatha Paris , a French jewelry brand for which she is the model. Aside from the two rings, she was also wearing a necklace also from the same brand.
And Taec and the other guys have nothing to worry about when Mingki ran off with Shin Hye because a VJ or a cameraman and either a writer or an assistant PD were definitely with her. I think PD Na and the woman PD (sorry forgot her name) are always in contact with their staff whenever any of the actors will leave the set. In this case,perhaps through cellphone because their set is not inside a studio where they can carry gadgets with earpiece to communicate.
A VJ will always be recording the action of the actors, thus why in episode 16 when Taec was all giddy and running around the set to follow Shin Hye's orders, there was caption that it was hard shooting with him perhaps because the VJ could not keep up with him