I am a professional statistician who has worked with surveys and self-rated medical studies.
Regarding Christmas trees and Orthodox Russians? Many joined Orthodox synagogues and attend regularly. But the Communists of the USSR repressed Christmas and transferred it to the New Year’s celebration. So Russians think of it as a New Year’s tree with none of the connotations it has for many American Jews.
Unfortunately many American Jews define themselves as “people who don’t celebrate Christmas” with little positive activity.
I never understand what people mean when they say “proud Jew,” as in the survey. I guess it means not hiding it but I am not sure what action it means. We need to think of the Jewish cultural orientation not in the terms of my grandparents, food, advocacy organizations, physical community — but as a legacy that is neither hidden nor acted on.