In one way, I'd have liked to have seen Rebecca around longer, just as I would have liked Mickey around longer. However, their deaths upped the emotional stakes in the battle for Ewing Oil and added to a truly great season. Rebecca's death was the proverbial straw that broke the camel's back in regards to Pam and Bobby's marriage. Even though it's completely unfair to blame Bobby or the Ewings for her death, it does make more sense that a grieving Pam would be in such a state of mind that she would feel she needs to separate from Bobby. Pam and Bobby were so much in love that it would seem forced if she left him just because of the contest set up by Jock. It could cause problems in their marriage, but Pam just walking out on Bobby and taking their son in the middle of an extremely stressful time in his life is immature, imho.
Of course, this all added to the layers of the season when JR called out Pam for her self righteousness. She slapped him not just for his lascivious comment about her in France, but also because he struck a nerve in that he made valid points.
In the following season Katherine makes a similar comment when Pam confronts her about that letter.
Pam: "He was still my husband!"
Katherine: "But you walked out on him. You didn't want him anymore."
Pam slaps her, and although Katherine was completely wrong in her actions, Pam wasn't exactly fair with Bobby by going off to France with Mark, but expecting Bobby and everybody's else to adhere to her high standards.
I only wish that scene between Pam and Katherine was a bit longer, and Katherine vented more about how Pam treated Bobby. She could also let her frustration out about how her father's company was divided, so two people(Cliff and Pam) got two thirds and he didn't even know them. In fact, Katherine could allude to a few other things in her life that contributed to her anger and hatred.
I noticed that when Pam meets Bobby in the scene prior to the Katherine slap, she comments on all the sad things that have happened: their divorce, Rebecca's death, Mark's illness. Yet, she never mentions
Jock's relatively recent death and the effect that must have had on Bobby. In the confrontation with Katherine a great line from the bellicose, blue -eyed brunette could have been. "You are so selfish, Pam. You walked out on Bobby and took Christopher. When Jock died did you even console him, or did you make it all about you?" Pam would have slugged her a good one or been so taken aback she would have fled to the French Riviera with Peter Richards

I do love the character of Pam, but sometimes it takes a villian to show the hero's they can be better.