What can readers infer about the ethics and attitudes of the mormon faith from what the author shares about her mother and grandmother? why does the author want readers to understand the mormon culture?

Well, we can see in the writing that a lot of Mormon's ethic and cultures seems unconventional or even unreasonable for most people.
But, the followers do that because they believe that it's all important to purify their souls, and i think we all should respect everybody's beliefs

I've actually never heard of the guy. but, atleast he doesn’t rap/sing about drugs and girls, but he still have a very high view of himself, which could possibly cause annoyance