There's a difference between adaptation; and retelling the story in a way that damages the integrity of the original. Many of the above changes don't make sense even within the movie's own material. Even if the books didn't exist, Faramir's filmic story arc (as just one example) would be a badly executed example of character development.
That's the real problem - nobody really cares about Arwen at the Ford vs Glorfindel; it doesn't change the story much at all.
And even changing characters somewhat but still having a development or purpose is arguably fine - it's the changes that aren't good in the context of the movie that are most baffling, especially considering the dedication shown in other areas of the films.
The retelling of a story can never damage the integrity of the original, and it is very foolish of you to even suggest that it could. The original is always the original, and is unimpacted by anything that comes after...
This is as silly as suggesting that Tolkien's work somehow tarnishes or damages nordic/germanic mythology. utterly ridiculous.
I get what you're saying but art doesn't exist in a vacuum. Newer works can add context and alter our perceptions of older works. Especially when people's first exposure to a work is an adaptation. Someone who has never read the lord of the rings, but has seen the movies several times will never be able to read the book without picturing Elijah Wood.
Strong feelings for an adaptation or a sequel can taint or enhance how someone feels about the source material even if the original was experienced first. For example, it's understandable if someone who really loved star wars before the prequels and disney acquisition found that they can't help but experience a sense of loss and disappointment while revisiting those original films knowing about midi-chlorians and how the franchise ended up.
The original works are unchanged, but in many cases the way we view and experience them isn't.
I also dislike the way Faramir was adapted but it makes sense. It puts a greater emphasis on the exceptionality of Aragorn by removing the complexity of the Faramir character and basically making him a second Boromir. Considering that the movie is necessarily a more condense experience than a book, it's a good choice.
