Okay, Amy, I'll start. Keep in mind I read it last summer so I'm not as fresh on the details as others who may have just read it.
I really loved this book, but I will admit, it took me awhile to make it through at nearly 900 pages. I remember telling my friend who read it after me (who was getting discouraged with the length) to "stick with it, you'll be so glad you did." So, to answer your question about the length, I'm undecided. I know when I got to the part (which I think was more than halfway through) where he began the story of the grandfather, Domenico, I was thinking, "what the...?" and at first, it was hard to switch gears into a completely different character's 1st person POV. As a result, I remember becoming discouraged with the length, like "Oh no! A story within the story". But that changed pretty quickly b/c the more I read, the more I developed a soft spot for Domenico. I loved his Italian dialect and old-fashioned views, and I was so happy for Dominick that he was finally getting the pieces of his past explained to him through reading it. But funny, reading as a writer (as per another thread on this board) I also recall thinking the one tell-all letter from Dominick's girlfriend (not Dessa, but the other one [can't remember her name--sorry]) rambled on quite a bit. Somehow, though, by the time I got to the end, I forgot all about that and understood why Wally Lamb had his reasons for including every single detail.
I love your last question as to whether there would have been any peace for Domick without Thomas's death... Very thought-provoking. It doesn't appear that he would have had any relief so long as his brother was alive. However, losing a brother--not to mention a twin brother--must be one of life's greatest losses, so I'm sure if Dominick's story continued on in a second book, we might learn of more angst in the long term, and perhaps learn that he wasn't at peace with his loss. But that brings me to my last comment on the book... I loved that Wally Lamb ended it with "I know this much is true." Hands down, that's my favorite ending to a novel, ever. It was perfect for Dominick's journey. Typically, I'm not a big fan of throwing the title in the novel, but this was an exception, and exactly what I needed to hear, before closing it (and finding a box of kleenex
.) It gave me hope that everything would, in fact, be okay for Dominick, and that after such a tumultuous thirty-some years, things were starting to look up!
I know I've rambled and probably didn't make much sense, but hopefully this'll get things started.