Several years ago, I bought a copy of Moby Dick at the local used books store. I have always enjoyed the movie version with Gregory Peck, so I thought I should read the book. Like the OP, I found large sections of text and even whole chapters that I felt could have been edited out. Some of this I slogged through and some I skipped entirely.
When I was done reading the book, I still felt that it was a worthwhile read and a reasonably good story. I also felt that it would have been an even better book if Melville's editor had been more ruthless in his editing. This is one book that definitely is better in the Reader's Digest Condensed Version.
BTW, the movie version was co-written by John Huston and Ray Bradbury. This is a classic movie. I don't even want to think about the Patrick Stewart version.
Stewart did an ok job as Picard (after season one), but the only movie I've seen him in where I thought he did a good acting job was Safe House. He really sucked as Scrooge. I haven't been impressed with him as a Shakespearian actor either.