Bea Benaderet’s last episode was when the youngest daughter gave birth to Kathy Jo. They had an actress dress up to look like her (she was shot from behind) and they dubbed Bea’s actual voice over that. It was very poorly done, if you’ve seen the episode.
Linda Kaye Henning (who played Betty Jo) said it was sad, because everyone knew this would be the last time any of them would get to work with her and she was going to go off and die. Indeed they never killed Kate off they just sent her on trips.
As for Valarie (AKA Valarie’s Family, AKA the Hogan Family) part of the reason Sandy Duncan was able to replace her was due to the fact Valarie Harper owned 25% of the show. It was in Harper’s interest to see that the show went on with or without her. She still got money from it.
I know Norman Lear said, that when Sally “Gloria” Struthers, threatend to leave, he told her to go. But when Carroll O’Conner, threatend to leave All In The Family, it came down to the wire. Remember the episode where Archie was gone for three episodes and was missing. Lear had intended to kill off Archie Bunker, but when push came to shove, CBS said “Look this is a huge hit, if it’s a choice between Lear and O’Connell, Lear would be out.” So instead it was said that Archie was on a three day drunk.
Also Redd Foxx and Demond Wilson walked off the set, it was obvious the show needed both of them and they were brought back. You remember when Grady was filling in for Fred. Those episodes were subpar.
The two most famous walk offs were probably Susan Sommers and Farah Fawcett. And we all know what happened to those ladies.