I think when going from a novel to a film it's understandable to be more obvious and heavy-handed, and to play up a certain theme, because you don't have the time to develop the story in the way a novel does. I think if they hadn't used the same actors, and also if they hadn't done the quicker jumps between stories, then it might seem much more disjointed, especially to someone who hadn't read the novel.
Good points. Still, I think making a bunch of characters go throughout time was too much, when it was only the possibility of the main character, with the birth mark. I haven't seen the movie yet, but the trailer was pretty expansive. I also thought adding a love story through the ages was reaching as well. Did they at least have the line where Cavendish called the reincarnation in the Luisa Rey story too new age-y? I thought that was an important part of the book that gave readers who didn't care for the theme of reincarnation an out, especially because I think the book is more about reoccuring themes of the human experience, not actually reoccuring people.