[Laitoste]

I don't see why having Merry at the Black Gate is a big deal, to be honest...when you cut out the scenes at the Houses of Healing, it would have been too confusing to not have him around. He would have just disappeared for large chunk of the film. People probably didn't even think twice about him being wounded--they probably assumed, that with so many wounded, Aragorn & co. would have just rounded up anyone able to stand.

I certainly agree that Pippin should have had the opportunity to slay a troll, and can't imagine why they didn't. They are, after all, big on "character growth," and the audience would have loved it.