Online searches only reference to Baldwin being "replaced" by Burnett, but I would love to know why, especially since Baldwin is still in the opening through episode 115 (where I left off). Casting Burnett felt like a stylistic choice for a colder Beth (which I feel Burnett is).
I think you're onto something there. I remember reading that Phil Carey would get his hand wet and get Jacquie Courtney to shake hands, getting the words she'd scribbled on her hand to smear and wash away. So the story went. The Buchanan gentlemen were known as being pranksters, especially back then.