Best known from Dynasty-where they became adept at bodice-ripping and doing love scenes without mussing their hair-these actors now practice those skills on daytime, with varying success. *MICHAEL NADER Then: Dex Dexter, Alexis’ love toy. Now: All My Children’s Dimitri, Erica’s love toy-until she stabbed him. He remains one of TV’s sexiest and most watchable actors. But lighten up, Mike-you growl so often I sometimes feel like I’m watching Smokey the Bear. *GEOFFREY SCOTT Then: Mark Jennings, Krystle’s ex and a tennis pro. Now: Guiding Light’s beleaguered businessman Billy. He took Billy over from Jordan Clarke and made it his own; GL isn’t using him enough these days. *WAYNE NORTHROP Then: Michael Culhane, the randy Carrington chauffeur. Now: Days of Our Lives’ saintly and stoic cop, Roman. He holds his own opposite scene-thief Deidre Hall, but where’s Roman’s vulnerable side? When his baby was kidnapped, shouldn’t he have cried?