PriceofMagic, as usual I agree completely with you. Regina was delighted to tell Rumple all about what happened to Belle. She enjoys every word, every second. And Rumple´s reactions are just painful to watch (what a great actor is RC! He says so much without saying a single word!). And yeah, I guess having Rumple saying Belle’s name outloud was a way to open the wound, preparing him for what was coming.
As for how Regina knew who Belle was, she seems to be always informed of what’s going on with Rumple. She as ears and eyes everywhere. And I’m sure that the gossip about Rumple taking Sir Maurice’s daughter reached her ears very quickly. I’m sure she was spying on the Dark Castle, just waiting for the chance… and that one day Belle came out, she was informed and well… the rest is history.