The irony of using Love Story for Ang is perfect! Though I suspect whoever picked it probably didn't think of that - they were probably just happy it was an easy song to get the rights to...
As for DS music, there are several pieces from the daytime show that could have worked, but none of them were used on the '91 series. There is a piece on the '91 soundtrack called Josette, Barnabas & Angelique, parts of which would have worked great for Josette and Barn, but I'm not so sure that the Ang part would have translated well to a watch.