Re: Running up stairways of falling rocks
While you can't always do book to fill 100% accurately you can do better than Jackson did. A confusing messed up impossible flight from the shire, that requires the extended edition DVD/BlueRay to remotely make sense. Aragon going from being a character full of purpose to one full of self doubt. A insane wobbly column in Moria and an Elvish army turning up out of the blue in Helms Deep are probably the deepest grievances one has with Jackson's effort. Also the elf/dwarf love story in The Hobbit, what the f'ing hell was that about.
You can do a much better adaptation than Jackson did. However it requires you to accept you are not better than the original author and bury any "artsy" tendencies you have that force you to make up shit because you have to have some way of expressing your creative desires.
To see how it can be done properly one just points to the BBC Radio adaptation of LotR's.