I found this slice of life of a play fascinating. I look forward to reading the original book and viewing the old movie for it that I found at the library as well. The play made for a quick read. I even started reading the next play, Life with Mother.
Modern readers will probably be put off by Father/Clare, but it's my guess that he was a product of his times. He is a commanding bully who gets pushed around quite a bit by his family. What's the phrase?—all bark and no bite? That seems to fit Father to a T.
There is a bit of swearing that seems excessive for the time it's set in. I believe that's for shock value and humor. While I didn't find it funny, it helped to characterize Father.