Sorry didn't see this been off the board a bit.
There isn't a "left" and "right" vambrace - both are exactly the same. It's not real noticeable but ASMUS did drop the ball there. It just bugged me so I use the old Sideshow vambraces. I don't consider it a deal breaker - I really like this figure, especially the way the chest piece looks like real leather.
No, I don't remember Faramir with the horn - but as collecting goes I like adding accessories now and then, that either evoke the film or are something a character might have used - jugs and bottles, knives and other weapons, torches, banners, etc. Either as a background piece or to change a pose. Other collectors display differently - movie only, museum poses, etc. Just depends on what you like.
IMO the big thing with me re Faramir was to make sure he had a bow, since that is when we first see him.