Thanks for the great review. I can understand your points, but it's important to remember that Wally and Clara are rather simple people, with simple minds. Zach said he wasn't gay, and they took that at face value, which means that, as they told Will, Will was either being a predator or he was going to inadvertently taint Zach's reputation. The rest of us would probably question things more intently, but those two accepted Zach's heterosexuality as a given. Now that the wool is pulled from their eyes, they have a new perspective.
And Clara is simply being that quintessential 50's/60's housewife, dutifully supporting her husband.
As for Will, he's learning to pick his battles. He was a peripheral figure in this one, and conducted himself like he was.