To me Kristin was a one note character who hated her sister. Sue Ellen and Kristin were sisters in name only which was obvious in Kristin's actions. She sleeps with her sister's husband, deludes herself into believing that he will marry her, shoots him when its obvious that he will never do that and frames her sister for his shooting. If Sue Ellen had not figured it out, she would have gone to prison and Kristin would not have spoken up. I never understood the crossover with Knots Landing. To me Kristin had no redeeming qualities. As for Kristin's death, shame the writers left it to the viewer's imagination. The pool should have been placed underneath the terrace if we were to believe that she either fell or was thrown from there.
As for Katherine, I had a lot of sympathy for her in the way he mother shafted her. Her father passes on, then he is introduced to two half siblings she has never hear of before, then her mother brings her half brother Cliff into her father's company where he has no business in and after her mother's death, fighting Cliff's fight with the Ewings, in Rebecca's will she makes Katherine part owner of a company that should be solely hers. I wish the writers had her challenge her mother's will in court instead of making her a psycho chasing after Bobby.