There is still a lot of tension between the book and the movie in a lot of respects. I can see both your points here. The problem arises when trying to take the movie at face value, versus incorporating your knowledge of the book and weaving that together with the movie as you watch it. You will come away with different impressions of the same story. Does that make any sense?
I've seen the movie more... so that is probably my over riding impressions.
I have read the Sam/Smeagol/Frodo scenes alot, mostly because I think they are wonderfully written, funny, and very, very good. In fact, to me, writing doesn't get any better than those three going through Mordor.