'Ulysses"

I recently finished reading Ulysses by James Joyce, and more recently completed two books about that book: Ulysses by Hugh Kenner and Ulysses and Us by Declan Kiberd.

While I realize that no one book can answer all of my questions about Joyce's work, I'm struck by the fact that even the EXPERTS can't agree on fundamental questions about what happens in the book. Depending on who you read, Molly Bloom in the last section is expressing a positive affirmation of life, masturbating or drifting off to sleep. In the Kiberd book, Molly is masturbating but Stephen is just peeing when he walks along the beach early in the book. According to Kenner, Molly is falling asleep, but Stephen is masturbating  on the beach. I also thought neither author quite captured what Joyce was trying to do.  I'd like to find one book that kind of ties things all together for me.

Here is Martin Amis on the difference between Joyce and Nabokov: "If you go to Nabokov’s house, metaphorically speaking, you get his best chair, in front of his fire, with his best wine. If you go to James Joyce’s house, you come into this big drafty edifice, and there’s no one there. And then you find him tinkering around in some scullery. And he offers you two slabs of peat around a conger eel, and a glass of mead."

Context here.