The Ent issue wasn't so bad...it was another of Peter Jackson's patented "changes which I hate in my gut because I'm a LOTR fan but in my head I realize were the right choice", which I far prefer to the 99% of other directors who make wrong, stupid choices.
The Faramir thing...jeez, that pissed me off, too. But I don't think I can say it was definitely the wrong choice until I see how it plays out in ROTK. I just finished re-reading ROTK over the holidays and I see how it could possibly be made to work.
Faramir maybe had to bring the hobbits to Osgiliath for a couple of reasons: firstly, Jackson needed to show how the Dark Lord's forces were advancing and ruining the cities of Men without resorting to even more "cut to an entirely different story" stuff. Great job--the Osgiliath sequences are awesome. Also, since Denethor totally bitches Faramir out for letting the hobbits go, maybe he felt the need to emphasize that Faramir could have brought them to the Steward and seriously almost did, but changed his mind. I just was unconvinced about the mind-changing, but like I said, ROTK or the cut scenes from TT might fix that somewhat.